In 1975, we recorded total body lengths, caudal lengths and sexes of the habu, Trimeresurus flavoviridis, gathered at Naze Health Center from all over Amami Oshima Island. As habu hatch from August to September, Fig. 1 shows the Peterson curve of total body length from one- to n-year-old groups. The frequency of individuals in each body length rank, as compared with Mishima (1961), indicates that the percentage of lower age groups is increasing nowadays (Fig. 2), namely, that the total number of habus on Amami Oshima Island is decreasing.

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In March, 1973 and July-August, 1975, the author surveyed the herpetological fauna, excepting the snakes, of Miyako-jima, Kurima-jima, Tarama-jima, and Minna-jima, Miyako Islands, Ryukyu Archipelago. With the exception of Miyako-jima. these islands were surveyed for the first time from the herpetological point of view. Three species of amphibians and nine species of lizards were collected. Bufo bufo miyakonis, Hemidactylus bowringi, Gehyra mutilata, and Emoia atrocostata were collected only on Miyako-jima, while Hemidactylus frenatus, Eumeces kishinouyei, and Scincella boettgeri were found to be distributed on all these islands. Gehyra mutilata was newly recorded from the Miyako Islands. Rhacophorus viridis owstoni, Rh. japonicus, Eumeces marginatus, E. elegans, and Ateuchosaurus pellopleurus, which have already been known from Miyako-jima, were not obtained in these surveys. Some findings on the breeding season and the habitat of several species are mentioned, and the morphological variations in Rana limnocharis limnocharis, Scincella boettgeri, and Takydromus smaragdinus are described. The distri- bution of gekkonid lizards is discussed with reference to their habitats.

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Observations on metamorphosing and newly metamorphosed frogs of Rana ornativentris showed that there is a considerable variation in the body growth and the sex differentiation of the gonads. The environmental water temperature is suggested to be related to this phenomenon. The mode of sex differentiation in amphibians has been classified into three types in relation to the time of metamorphosis (Witschi, 1929), and according to this classification, the mode in Rana ornativentris inhabiting the Niigata district belongs to the semidifferentiated type. It is conceivable, however, that the conception introduced by Witschi has no significant meaning embryologically.

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Intersubspecific hybridizations among common toads were made, and the morphological characters of the hybrids thus obtained were examined. Females of Bufo bufo japonicus from Momoyama, Kyoto were crossed experimentally with males of B. b. miyakonis from Miyako Is., Ryukyu Archipelago and a male of B. b. spinosus from Banyuls, Southern France. Early development of hybrid embryos proceeded in the same normal way as the control embryos, although the percentages of normally cleft eggs were slightly lower in the former than in the latter. Most of the normally cleft hybrid eggs became normal swimming tadpoles and attained the completion of metamorphosis. The japonicus _??_ × miyakonis _??_ hybrid tadpoles had longer tails than the control, while the hybrid japonicus _??_ × spinosus _??_ tadpoles had the smallest tails. Immediately after metamorphosis, the hybrid young toads had shorter hindlegs than the controls and the older young hybrids of two to four months after metamorphosis differed markedly from the controls in this respect. Some of the male hybrids of japonicus _??_ × miyakonis _??_ attained sexual maturity in the fall. Histological examinations of the young toads revealed that both male and female gonads of japonicus _??_ × miyakonis _??_ were developing normally, whereas no normal spermatogonia were developing in the testes and the ovarian structures were completely destroyed in the japonicus _??_ × spinosus _??_ hybrids. These results seem to indicate that the genetical isolation is somewhat advanced between Japanese japonicus and French spinosus, and that they could be treated as two distinct species.

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Mauremys japonica (=Clemmys japonica) is the second most abundant turtle species in the Kyoto area. It lays eggs in June and July, and hatchlings appear from the last past of August to early October, as shown in Table 1. In our observations, only one clutch is laid annually, and no eggs winter in the ground (Cf Fukada and Ishihara, 1974, Chinemys reevesii). The newly emerged hatchling has a carapace length of 3.5cm and a weight of 8g, as shown in Table 2.

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1) Although Eumeces okadae is endemic to the Izu Islands, its range is only partly known because of the deficient study of the herpetofauna in these islands.
2) Its range as known up to now covers the five islands of Niijima, Shikinejima, Kozushima, Miyakejima, and Hachijojima. And there is a report that indicates its presence on Hachji-kojima (islet) and Aogashima (island), but for these islets a reinvestigation is needed. For the present, therefore, they are not included in the range.
3) In the present paper I report a newly recorded range of Eumeces okadae on the islands of Oshima, Toshima and Mikurajima.
4) For Aogashima (where Eumeces latiscutatus has been reported to live, but considered from the actual range of Eumeces okadae it may, with a reinvestigation, prove to be Eumeces okadae) and the neighbouring islets of the above-said eight islands in the range there is a possibility for Eumeces okadae to be found. On an island in the south of Aogashima, however, there is little hope of its discovery.

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