This paper provides the morphological descriptions on the first to the seventh molting stages of Caridina denticulata ishigakiensis which was reared under laboratory condition and on its egg number and size. The present species bears a few eggs of large size, and the eggs hatch out as non・pelagic larvae of benthic habit. The newly-hatched larvae have the stalked eyes and all the appendages of adult form but uropods, although some zoeal characters are still remained.

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1. The Japanese Gecarcinid fauna includes four species distributed into two genera (Gecarcoidea lalandii, Cardisoma carnifex, C. hirtipes, C. rotundum). 2. Gecarcoidea lalandii is known up to now only from the souther-most islands. The occurrence of Cardisoma rotundum is restricted to high rocky islands. C. carnifex and C. hirtipes occur as far north as Amami-Oshima. 3: The distribution border is apparently formed by the 20°C-Isotherme of sea-water in February, so that both species are expected to occur on Tokara-Gunto, too.

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The Board of the Crown Prince's Household of Japan was kind enough to send the author 13 living specimens of the Hawaiian fresh-water shrimps for his study, in February, 1975. According to the information from the Board, their localities are unknown in detail. As the result of the author's examination of those shrimps, it is found that 12 specimens belong to Caridina acuminata which has been reported from Bonin Islands (STIMPSON, 1890) and Ito, Sagami Bay, Japan (BALSS, 1914), and that 1 specimen, to Macrobrachium lar distributed ,widely throughout the Indo-West Pacific region from E. Africa to the Riukiu Islands, Micronesia and Marquesas Island. Their body-length excluding rostrum : the former specimens are 14.5, 15, 16, 17mm respectively in female and 13.5mm in male, and the latter, very young male, 24mm. So far as the author knows both the said species have not hitherto been recorded from the Hawaii Islands. The colouration of C. acuminata is Characteristic as follows : marked with many dark brown coloured spots which being arranged longitudinally in two rows over the lateral surface of the abdomen. The upper row is variable to the streak. The dactylus of the fifth leg is furnished with 8 to 15 bristles on the posterior margin.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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In this introductory report on the crabs of the Ogasawara Islands altogether 123 species of 12 families were enumerated on the authorities of the previous workers. They are 2 species of the family Dromiidae, 4 of the Calappidae, 1 of the Hymenosomatidae, 13 of the Majidae, 5 of the Parthenopidae, 6 of the Portunidae, 63 of the Xanthidae, 2 of the Goneplacidae, I of the Pinnotheridae, 6 of the Ocypodidae, 18 of the Grapsidae, and 2 of the Gecarcinidae. Even if the identifications may be not always correct in some xanthid and other species, the monumental records are worthy as the indicators of the Ogasawara Islands crabs unless there are no definite reasons to reject the names. Most of the species are widely distributed in the southern Indo-West Pacific waters, differing as a whole from the crab fauna of the Japanese mainland.

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This paper deals with the decapod crustaceans obtained from the stomachs of four species of fishes collected at the rocky bottom of the shallow water. The fish species are Epinephelus fasciatus (FORSSKAL) of the Serranidae, Gymnocranius japonicus AKAZAKI and Lethrinus variegatus VALENCIENNES Of the Lethrinidae, and Parupeneus barberinoides (BLEEKER) of the Mullidae. All the species are useful for food, and the first or the blacktip rockcod is the most abundant along the entire coasts of the islands and islets of the Ogasawara Islands. Among these only in the second species three specimens are available for the examination of the stomach contents. The identification of the species is rather difficult in some cases in which there are only the fragments of the carapace and chelipeds. In this paper altogether 20 crab species including some questionable ones were identified, and two pairs of chelae obtained from G. japonicus, which are probably referred to those of Lissocarcinus or allied genera of the Portunidae, are remained uncertain. There are otherwise a large and a small chelae of snapping shrimp referable to Alpheus, a chela of Callianassa which is an anomuran decapod called mud or ghost shrimp, two specimens of Munida or lobster krill, a right or small cheliped of hermit crab referable to Calcinus, and two specimens of grapsid megalopa larvae. Although 123 crab species have hitherto been known from the Ogasawara Islands, it is remarkable that 11 of 20 species identified at present are new to this area. This fact indicates that the rocky bottom of the shallow or rather deep water is scarcely exploited. This sort of reports may be therefore of certain use not only for the systematics of the crustaceans, but also as the indicators for the ecology of the fishes and crustaceans. As summarized in Table 1, it is remarkable that 7 of 20 species are referable to the Majidae, representing 35% of the species recorded. The families subjected to food of fishes are the Dromiidae, Majidae, Parthenopidae, Portunidae, Xanthidae, Goneplacidae, so that the ratio of the known species of the Majidae among these families are only 14%. On the other hand, the low percentage of the Xanthidae for food is also remarkable, being 30% at present contrary to 69% in the known species of the above families. This fact may be attributed to the different habit and habitat, and it is briefiy mentioned that the camouflage with the seaweed, sponge or other inorganic matter may be not always an effective means for the defence against the fishes. The relation between the crab and fish species is summarized in Table 2. This suggests that as for the habit of food search Parupenus barberiwoides may be somewhat different from Gymnocranius japonicus and Epinephelus fasciatus.

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1) The larval development of the subfamily Sesarminae, the land crabs, has been studied from the first zoea to megalopa, using the following four species as materials : Sesarma (Sesarma) intermedia, Sesarma (Parasesarma) erythrodactyla, Sesarma (Chiromantes) bidens and Cyclograpsus intermedius. 2) In order to clarify the specific differences of the larvae in this subfamily, several comparisons have been made among these four species as well as with other five species, the developments of which were reported in one of the auther's previous papers (1974) : Sesarma (Parasesarma) picta, Sesarma (Holometopus) haematocheir, Sesarma (Holometopus) dehaani, Helice tridens tridens and Chasmagnathus canvexus. 3) The number of zoea stages comprised in entire course of development differs according to genera, this being four in S. (H.) dehaani, S. (P.) picta, S. (P.) erythrodactyla, S. (C.) bidens, Chasmagnathus convexus and five in the others. 4) Of the characters which are constant through all the stages of zoea, the followings are found common to all the examined species of the subfamily: (a) The arrangement of setae on some of the limbs: the endopod of the maxilla I, 4.1(5)-1; the protopod of the maxillipede I, 3.3.2.2(10); the same of the maxillipede II, 1.1.1.1(4); the endopod of the maxillipede II, 3.3(6)-1-0; (b) The maxillipede I has a chromatophore on the protopod. (c) The telson belongs to A_0-type. 5) Of the characters which are constant through all the zoea stages, the followings are different according to genera. (a) The lateral spines of carapace which are present in Helice and Chasmagnathus are absent from Sesarma and Cyclograpsus. (b) The arrangement of setae on the endopod of the maxilla II is 3.2(5) in Sesarma, whereas 2.2(4) in the others. (c) In Cyclograpsus, the protopod of the maxillipede II has chromatophores which are absent in the others. (d) Helice and Chasmagnathus carry lateral spines on the pleomere IV, but Sesarma and Cyclograpsus are lacking in these. 6) Of the characters which undergo changes as the development progresses, the following are common to all the species examined : (a) Judging from the first stage of the development, the endopod rudiment of the antenna II, pereiopods and pleopods are more or less uniform in their growth rate through all the species. (b) In the zoea stage II, a plumose seta appears on the basis of the maxilla I on outer side to persist through subsequent stages. (c) The maxilla II has a feebly bifurcate basis, and the setae are arranged as 4.5(9) in the first two stages. (d) The maxillipede I has setae as 4.1(5)-2-1-2-2 on the endopod in the first two stages. (e) Natatory setae on expods of the maxillipedes I and II increase in their number after a formula : 2×(S+1), where S is the ordinal number of stages. (f) The articulation of the telson becomes distinct in the zoea III. (g) The endopod rudiment of antenna I becomes distinct in the final stage of zoea in Helice, Chasmagnathus, and Cyclograpsus, but it does not exist even in this stage in Sesarma. (h) In the scaphognathite of the maxilla II of Sesarma, the plumose, setae increase with the stages as follows : zoea I, 4.1(5), zoea II, 5.3(8), and zoea III, 7.4(11). (i) Only in Sesarma, the telson is armed with six setae between the caudal furcae through all the stages. 7) Features of megalopa common to all the nine species of Sesarminae are as follows: (a) The maxillipede II has one outer seta on the exopod segment I. (b) The maxillipede III has one seta on the exopod segment I. (c) The pleopod IV lacks plumose setae on the coxa. (d) The uropod which bears one seta on the coxa lacks endopod in all the members of Sesarminae. 8) Generic differences in the characters of megalopa are as follows : In Sesarma, the antenna I lacks the endopod, the mandibular palp bears four setae in the distal segment, the maxillipede I carries three plumose setae on the proximal exopod segment

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According to Dr. T. Sakai, President of The Carcinological Society of Japan, two ocypodid species, Ocypode stimpsoni ORTMANN and O. cordimana DEsMAREST have been known from Sagami Bay. Recently, some specimens of O. ceratophthalma (PALLAS) (juvenile form) were obtained from the same area. The description and illustration of this specimens, comparing with O. stimpsoni and O. cordimana, were made in this paper.

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This report deals with colourations of freshwater crabs, Geothelphusa dehaani (WHITE), with special reference to its distribution in Kanagawa and neighbouring Prefectures. In adult crab, the colourations appeared on the carapace and thoracic legs of this species can be distinguished fundamentally in three types as shown below : [table]

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The writers found recentry many nodulose tubes from the basal part of the upper Narita formation (late plistocene) at the east corner of Shimoyokoto village, Yokoto-Machi, Chiba-city, Chiba prefecture. The tubes consist of mud and sand mixture, some one is preserved in good condition and remains callianassid crustacea (Callianassa japonica ORTMAN) in it. These specimens had been kept of nearly in living position, that is, they have large and small chelipeds in pairs and fragile jointed waking appendages. On the other hand, the remains which were found outside of the tubes had been polished and detached by water current and some of them has small holes on the surface which probably been challenged by scavenger or certain carnivorous animals. This finding suggest, more or less, post-mortem changes. In short, the writers are strongly inclined to consider that the good preserved individuals in tubes might have been autochthonous fossils, and the others died outside of original burrows.

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