In this paper are given notes on, or descriptions of, some interesting or rare fishes, including one new genus and three new species from Japan, the Ryukyus and Pescadores (Formosa Strait.) The specimens observed are deposited in the Zoological Institute, Faculty of Science, University of Tokyo, or in the Biological Laboratory, Imperial Household.
Before going farther, the author wishes to express his hearty thanks to His Majesty the Emperor of Japan, who has willingly lent him the specimens of Pseudocepola taeniosoma KAMOHARA and Osbeckia scripta (LINNÉ) and the holotype of Mars auropunctatus n. sp.; all these specimens were collected by His Majesty himself from the eastern part of Sagami Bay. The author is indebted to Mr. Masao YOSHIDA of the Misaki Marine Biological Station for his assistance in examining the sexual differences in Monacanthus cirrhifer TEMMINCK et SCHLEGEL, and to Mr. Tsugio SAITO of the Imperial Household, who was kind enough to take the photographs of the specimens of the same species. The author is much obliged to Dr. Jean Clark DAN for her kindness in correcting the English of the manuscript.

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1) The experiments were carried out for the purpose of knowing the influence of the waste liquid, drawn out of the alcohol factory adopting mainly the sweet potetoes as the raw material, upon the development of the eggs of Cyprinus carpio and of Plecoglossus altivelis.
2) The boundary concentrations of the waste liquid, in which the eggs of Cyprinus and of Plecoglossus are possible to hatch, are 1/50 and 1/400 respectively, the ratio of both being 1: 1/8.
3) The ratio of the resistant forces of the eggs of Cyprinus and of Plecoglossus for the waste liquid may be recognizable to be 8 (Cyprinus): 1 (Plecoglossus).
4) The boundary concentrations of the waste liquid, which are not effectual for the hatch of the eggs of Cyprinus and of Plecoglossus, may probably assume to be below 1/1000 and 1/1200 respectively.
5) Each resistant force of eggs of Cyprinus and of Plecoglosus for the waste liquidshows the postive correlation to the tenacities of the respective adults.

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1. 104 immature individuals (11.4-18.0cm in body length) of Ophiocephalus argus CANTOR (Ophiocephalidae, Teleostei) obtained from Lake Ezu near Kumamoto were examined for the purpose of knowing the relation of the rates of increase of the brain weight, of the body length and of the body weight.
2. The rates of increase of the body weight is larger than that of the body length.
3. The rate of increase of the brain weight is larger than that of the body length.
4. The rate of increase of the brain weight is smaller than that of the body weight.
5. If we apply the formula “Y=ax³” to the relation between the body weight (Y) and the body length (X) then the constant value (a) is calculated to be 0.0147 in male, 0.0148 in female.
6. When the relations among the brain weight (W), the body weight (Y) and the body length (X) are represented by the formula “W=log X×√Y×C” the constant value (C) is generally shown by 0.0277 in male, 0.0275 in female.
7. The increase rates of the brain weight, of the body length and of body weight show the sexual difference, being higher in male than in female.

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This study has been made as to the length of the digestive time spent by the mud loach; the main points of its result are as follows; I had beforehand put some cobitises in a pisciculture bath and then as feed-stuff gave them some raw flesh of Viviparaus malleatus and red-shrimps (Penacopsis) which was dyed with edible rouge. Then I observed the length of the time of its digestion by them, seeing the changes of the contents in their alimentary organs.
Thus I found that the loach which was given raw flesh of Viviparaus malleatusas feed needed about 20 hours almost to complete thedigestion in their stomaches, while they needed less than 20 hours to excrete the indigestible stuff; that the loach which was given that of red-shrimps needed about 24 hours in the former case and about 20 hours in the latter case even in the quickest time; and that when the feed stuff was over-eaten the raw flesh of both Viviparaus malleatus and red-shrimps needed longer hours to be digested.
It seems that these facts probably have some close connections with the stomach which may be called a store-room of food and the intestine which has very weak digestive power with respiratory function. At any rate, I think, these are very interesting phenomena.

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This study was made to know the influence of the sunshining hours at the seven stations, Takamatsu, Tokushima, Wakayama, Sumoto, Osaka, Kobe and Okayama, upon the group of the porgy (Pagrosomus major) which are caught to the maximum appearing at the four fishing grounds, namely Sanbonmatsu, Sakate, Yasuda and Fukuda. The main points of its result are as follows:
It was found that in case, where the lateness or earliness of days when these fish were caught to the maximum was calculated to be±1 day, the maximum group of the caught porgy bathed daily the natural light on an average 343.1±4.2 minutes during 326 days from June 1 to April 23 of the next year; and that they daily bathed it on an average 323.7±10.5 minutes during 81 days from February 1 to April 23.
And the causes of appearance of lateness or earliness of the days when porgy are caught to the maximum were found to be resulted by the length of sunshining hours for the growth of gonad and the activity of the porgy.
And then, it was found that the migrating course of porgy group in the days when they are caught to the maximum can be presumed upon comparing the time of appearance of these days with the length of the sunshining hours.
It was found that in cause, which produce the earliness or lateness in spawning migration movement of porgy group in the days when they are caught to the maximum, is firstly under the control of the length of the sunshining hours and secondly of the temperature of the seawater in the fishing season.

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This study was made in order to have the data for forecasting in a short-term the first fishing day for porgy which are caught with the fishing implement “ Masuami”in spring at the four fishing-grounds, namely Sanbonmatsu, Sakate, Yasuda and Fukuda. The main points of its result are as follows;

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This is the report of my research made to examine the mortality of the eggs and larvae as the progeny from the crossing between M. anguillicaudatus and C. carassius or between the former and C. auratus, and to observe morphologically external and internal characters of hatching larvae.
At the gastrula and the hatching stage, more striking increase of mortality was shown in interfamiliar crossing eggs and larvae than in normal ones; moreover, all these hybrids died in 3-20 days after hatching.
In almost all of these hybrids, some kind of sap began to fill in between the epidermis and the york, causing the edema. Observing the sections of these hybrids, I found that these were conspicuons obstacles of development in the pronephric duct and pronephric chamber, the results being either collapsed ones or their non-existence. However, in those hybrids which were free from the edema, the pronephric system was found normal.
Again, in some hybrids I observed the hypertrophy of pronephric duct, though in the case only where one side of the pronephric duct was closed or not present at all. But, in the case where hypertrophy of pronephric duct continued to the anus, the larva was found free from the edema.
From the above mentioned facts, I think that the factor that causes the edema is the obstacle in the excretory function of pronephros. On the other hand, hybrids which had not obstacles of development in the pronephric system could live for 10-20 days after hatching, while all the edematous larvae died in 3-5 days. From this, I think that the edema is one factor of the death in these hybrids. Again in many hybrids, I found striking obstacles of development in the tail, abdomen, heart, notochord and blood vessel causing a great irregularity in the pulsation of heart, and the inability of swimming and feeding in the hybrids. From this I think that the death of the hybrid is caused not by the edema solely, but many other factors are working at it.

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This is a part of a series of experiments, which have been carried on to see the influence of environmental conditions to the activity of locomotion of fish. Measuring how frequent the fish would cross an assumed central septum of the tank to express the activity of fish-author is using the term of “frequency of transfer” to denote it - under various conditions. This time, the experiments were done to see the activity of gold fish, expressed by “frequency of tranfer, ” in various size of the. tank, which were obtained by changing a length of the same long tank by moving one septum from one end to the another of the tank (Fig.1)
A series of experiments were undertaken by the following order. At first, whole length (150cm) of the tank is used and “frequency of transfer” is obtained. Next by shortening the length of the tank, one by one the same tank was utilized as smaller four size tanks, and in each case the same experiment was made until the length of tank is 37cm. After these, on the contrary, in the same degree of length, the four experiments were done one by one until the length of the tank became whole length. This one series of the experiments were repeated five times. And about the “frequency of transfer” in each series of experiment the average obtained for each size of the tank respectively as shown in Table 1 and Fig.2 and 3. Examining these figures, it is recognized that the “frequency of transfer” has a fair straight line relationship with the length of the tank as shown in Fig.3. However, when the length of tank is going to be shortened it has more figure of “frequency of transfer” than when it is going to be enlarged (Fig.2 & 3). This is considered that the speed and the distance of the fish swimming around here and there is almost constant so the activity of fish, when it is expressed as “frequency of transfer, ” would be the more in the smaller tank than the larger tank. And when the experiments were carried on in the order of shortening the length of tank, the fish is more actively moving than when it is in order of enlarging the tank. This straight line relationship tells us that no effect of change of other enviromental conditions happens during this series of experiments.

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The part four of this article contains descriptions of life colors of the species nos. 59-76, with some interesting notes on the fishes found in Suruga Bay and others. The interesting species are as follows: Arengus sagax with notes on the variations of spottings on the body; characteristics of Parasalanx ariakensis from N. Kyushu; variations of members of anal organs found in eleven species of the Lantern-fishes of Suruga Bay; life color of the sea-run form of Triborodon hakonensis.

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In the A-series, thirty chum salmon alevins were immersed in the solution of 1/1, 000, 000 of thyroxine and 1/3, 000 of thiourea, respectively, for six weeks immediately after hatching, and in the B-series, thirty alevins were immersed in the solution of 1/1, 000, 000 of thyroxine for seven weeks, one week after hatching, the effects of these treatments to salmon larvae were observed. The same number of control groups were held in tapwater under identical conditions.
The following results were obtained:
1. In the both series of treated larvae, a marked inhibition in weight increase namely, the growth rate and also a delaying of the rate of absorption of yolk sac were observed. In the body form of the larvae treated by thyroxine, the broadening of the head, such as protrusions on the top of the head as well as posterior edge of the opercular and enophthalmos like conditions, was observed. But the developments of thetrunks, caudal, and fins, except elongated pectoral fins, were very poor. These modifications were more remarkable in the B-series.
The marked changes were not observed in the larvae treated by thiourea, besides the immature characteristic which were somewhat kept in the body form.
2. In the both series, the colorlation of the larvae treated by thyroxine showed a pallor, namely, premature silverication, which was produced by the deposition of excessive guanine. On the other hand, the coloration of the larvae treated by thiourea showed no change.
3. In the control fish, the histology of the thyroid gland showed a figure of functional and hyperactivity with cuboidal epithelium and vacuolized colloid.
On the contrary, the thyroid gland of the larvae treated by thyroxine in the both series appeared in the hypofunctioning figure with flattened epithelium and dense colloid.
While the thyroid of the larvae treated by thiourea revealed pathological hyper functioning with obvious hypertrophic columnal epithelium, number increase and size decrease of follicles, and lack of colloid. Furthermore, hypertrophic cells of pituitary also observed in the thiourea treated fish.

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The carp has the lateral canal organs and pit organs as the neuromast (Fig.1). The present paper deals with the development of these two kinds of sense organs. The first primodia of the supra-orbital organs and main lateral canal organs appear as placodes when the embryo is about 24 hours old from fertilization (water temp., 18-21°C) (Fig. 2, a, b). The placode sop) of the supra-orbital organ streches along the dorsal edge of the optic vesicle, and the rudiments of the main canal organs consist of three placodes (mlp) which are arranged to form a file on the trunk. These placodes are iudicated by slight thickening of the epidermis in sections (Fig.3, a), but are not visible by the surface view. In a 41-hour embryo, two new placodes appear (Fig.2, b): one, behind the optic vesicle, and the other, in front of the auditory vesicle. These two placodes (iop.omp) form respectively the primodium of the infra-orbital and operculo mandibular canal organ. In a 63-hour embryo, the supra-orbital and main canal placodes begin to divide into the distinct cell masses (Fig.2, c). The cells which form these masses are slightly larger the ordinary epidermal cells and are regularly arranged with radial manner (Fig.4, a). By 24 hours after the hatching, the remaining placodes (iop, omp) are also divided into the cell masses (Fig.5, a). Then, the cell mass comes to have an appearance of a flat dome with a vesicle-like space which sets at the top of this structure (Figs.3, and 4; b). Next, the cell mass begins to differentiate into the sense organ by the name of neuromast, and thus sensory cells, supporting cells and cupula become discernible (Fig.3, b, c). The pit organs are formed after the hatching of embryo and seem not to be drived from the placodes. By 7th day after hatching, the number of the pit organs increases rapidly and attains the same condition as in the adult fish (Fig.5, b). Both the canal organs and pit organs formed by the above-mentioned process project considerably out of the surrounding epidermis (Fig.6, b), and they are easily recognized as white projections when they are magnified about 25 times under the microscope (Fig.6. a). The canal organs, however, begin to sink under the epidermis and to be enclosed in the canal, through the similar process as that described by Aldus ('89). But, the pit organs do not sink under the epidermis.
From the results above-mentioned, all the canal organs excepting those of the supra temperal commissure belong to the “primary neuromast” named by LEKANDER ('49) and the most of the pit organs seem to belong to the “third type of neuromast.”

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