This fish has sensory papillae on the skin of the head. These sensory papillae are easily detected as a whitish spot by the naked eye examination (fig. 1). Each papilla exhibits considerable variation in its size. In the specimen of 50 mm body-length, the papilla in the mid-size is about 0.2 mm in diameter in its base, 0.05 mm in diameter in its apex, and 0.08mm in its height. These papillae are arranged in definite lines in parallel with the long axis of the body: the pattern of arrangement of the papillae belongs to “the longitudinal type” named by AURICH (1938) (fig. 2 a, b). The histological structure of the papilla is shown in Fig. 3. The papilla projects prominent above the surrounding epidermis and has a dome-shape in its section. The specific cells with elongated pear-shaped form crowd closely in the outer portion of the papilla. These specifioc cells seem to be the sensory cells and be deprived of the cilia or sensory hairs. The specific cells are surrounded by extremely long cells which seem to be supporting cells. Each papilla is situated upon the corium which elevates upward the base of papilla and is penetrated by nerve fibres. These nerve fibres seem to reach to the above-mentioned specific cells, but the writer could not ascertain the relation between both. The writer's opinion about this question will be publised in accordance with hisfuture progress of investigation. It is interesting to note that these papillae seem to be generally prominent in such fishes as those equipped with poor canal line system.
The author has enumerated four species of fishes with some notes. Among them Ranzania makua and Trulla itina are newly added to the list of the fishes of Suruga Bay, Japan. Hypoptychus dybowskii should be. erased from this' list.
1. Materials and Methods. Materials are the teeth of upper and lower jaws of five kinds of the porgies which are common in Japanese waters. They are Pagrosomus major (TEMMINCK et SCHLEGEL), Evynnis japonicus TANAKA, Sparus swinhonis GÜNTHER, Taius tumifrons TEMMINCK et SCHLEGEL) and Argyrops cardinalis (LAÉPÈDE. All of them are 20-60 Cm in length. Methods used were: microscopic observation of the bleached-bone, and microscopic observation of ground, paraffin and celloidin sections. 2. Findings. The teeth consist of crown and root areas; they are joined by a contact area; and they are together surrounding the pulp tissue. The root area spreads to jaw-bones. a) The teeth are divided into outside and inside teeth by their arrangement. Two or several of the anterior-outside teeth are especially large and spear-form; inside and posterior-outside teeth are of various size and bowl-or, grain-form. However, only Taius tumifrons does not show the bowl-form. Color is yellowish-white or light yellow, but Sparus swinhonis shows a tinge of black. b) The crown area consists of enamel and dentin (inside dentin, outside dentin); and the root area consists of dentin. The enamel is the so-called “tubular enamel” in which the tubules of fibrous structure cross each other in middle layer of enamel, and it may be seen as a brown zone. The outside dentin is placed between enamel and inside dentin, seems to be a primary cement; and dentinal tubules have branches and end in the middle layer of the outside dentine. The inside dentin has dentinal tubules similar to human dentin, and these tubules are running with S-shaped curves. In this layer are found the dentinal lamellae, Owen's contour lines and praedentin, but the writer has never seen interglobular dentin and Tomas' granular layer. In the dentin of root area is found a osteoid-dentin that has dentinal tubules near the crown area and osteodentin which has no dentinal tubules and is under the osteo id-dent in. c) The pulp tissue chiefly cons: sts of fibroblasts and fibrocytes. There are odontoblast layer in the surface of pulp tissue, and the pulp tends to be fibrous. The dentinal fibers are long, slender protoplasmic processes projecting from the cell into a dentinal tubule and running through the tubule to the outer surface of the dentin. d) The contact area is fibrous, not calcified, and seems to be a retentive apparatus of the crown area. e) Moreover, there is a fibrous layer which seems to be a “Grenzfasershicht” as stated by M. MORGENSTERN.
While examining many specimens of fishes from the depth off the coasts of Hokkaido and its adjacent regions, the author has found some interesting species which have hitherto been little known or unrecorded from the waters of Hokkaido and northern Japan, as well as some others which require criticism from the ichthyological point of view. Here the author wishes to report his observations and gives some ichthyological annotations on them in following seric.s of this study. The materials for this study were chiefly obtained from the catches brought up by the bottom-twawl or “Kisen-sokobiki” from a depth about 150 to 1200 m, at the fishing grounds and landed on the harbors at Kushiro, Abashiri, Mombetsu of Kitami Prov., Wakkanai, Otaru, Muroran and Hakodate, etc. The majority of the materials were collected by the author himself from the spring of 1949 to the winter of 1952 at fish-markets, but some others were given to the author by the branches of the Hokkaido Fishery Experimental Station situated at the cities stated above. The specimens thus collected amount to over one thousand in number and contain about 190 species belonging to 130 genera and 41 families as far as the author has studied to this day. In addition to the above mentioned materials, the specimens of several interesting species collected by Mr. T. HIKITA at various places in Hokkaido in many years were placed in the author's hand for a closer examinations, and also some imperfectly known fishes were given to him by Mr. H. Misu who spared them from his collections made in the depth of T the northern Japan Sea by the aid of a bottomtrawel net of the training vessel “Hokusei-maru” attached to the Faculty of Fisheries, Hokkaido University, from May to October in 1951. In August 1952, HIKITA and Misu published their report on the deep-water fishes based upon the above stated Misu's collections. But they have committed some -obvious mistakes in their identification of species. For instance, Myoxocephalus tuberculatus SOLDATOV & PAVLENKO in their report (p.35, pl. VI. fig. 4) is nothing but M. ochotensis of ScHMIDT. and Cyclolumpus asperrimus TANAKA (p.40, pl. VIII. fig. 1) is a species of the genus CyclolumPus birulai (Popov) as one can understand from their desdription and figure. So their report is in need of revision, and the author will freely give his opinion on the subject concerned in the present article. In the following description of various parts of body in each species, the measurement is done as below: The body length is measured from the tip of snout to the base of caudal fin; the length of head, from the tip of snout to the extreme posterior margin of opercular flap; the depth of body is indicated by the vertical breadth of the deepest part of body; the length of snout is represented by the length between the tip of snout and the extreme anterior margin of orbit; the length of maxillary is measured from the tip of upper lip to the posterior end of maxillary; the diamater of orbit is the horizontal distance between the opposite margins; the width of interorbital space is meant by the distance between the upper margins of eyes; the length of caudal peduncle is shown by the length between the base of hindmost anal ray, to the base of caudal fin; the depth of the same is the least vertical width of caudal peduncle; the length of each fin is represented by the length of its own longest ray. The author wishes to express here his sincere gratitude to his teacher Mr. T. HIKITA and Prof. S. SAITO, for their kind guidance and valuable advices throughout the course of this work. He also wishes to thank Prof. J. TOKIDA for his correction of original manuscript. Further his thanks are due to Prof. S. SATO who has given him various advices as well as permission to use his library freely; and to the staff members of thkn-abstract=
The regional variations of number of the anal fin-rays were examined of 4437 wild specimens of Oryzias latipes collected at 56 different localitis in Japan. The results obtained are given in table 1, as “ frequency distribution curve, ”in fig. 1. Fig. 2 is a map showing the mean value of the fin ray counts of the fish caught at the respective locality. From the results, the following may be concluded: (1) Within the neighbouring localities belonging to the same watershed, the averages of the number of the rays do not show a significant difference. (2) The differences are often significant among the fish living in the waters situated at the isolated regions. (3) The number of the rays does not show a decrease or an increase according to the differences of the circumstances (temperature, for instance) at the locality. (4) The geographical variation is caused not by the agents of environment, but chiefly by the differences of the gene-constitutions.