HEEPETOLOGY OF JAPAN. 413 



Genus EM YDOCEPHALUS" Krefft. 



1869. Emydocephalus Krefft, Proc. Zool. Soc. London, 1869, p. 32i (tyi)c, E. an- 

 nulatus). 



Boiilenger, with specimens of another species of tliis genus before 

 him, still persists (Willey, Zool. Results, 1898, p. 57) in placing these 

 snakes in the genus Aipijsurus which he has diagnosed as having the 

 ''maxillary a little longer than the ectopterygoid [transpalatine] ; " 

 ''poison-fangs . . . followed, after a short interspace, by 6 to 10 

 grooved teeth." 



In the genus EinydocepJialus, on the contrary, the maxillary bone is 

 shorter than the ectopterygoid, very much as in Laticauda (see Bou- 

 lenger, Fauna Brit. India, Kept., p. 394, fig. 116a) even slightly more 

 reduced. Behind the fang there is no trace of another tooth, such as 

 is found in Laticauda, not even an impression on the surface of the 

 bone. Add to this the remarkable and apparently constant fusion of 

 the median lalnals, which some authors might regard as a good generic 

 character in itself, and the status of Emydocephalus seems assured. 

 vSo far as I can see, it is more closely allied to Laticauda than to Aipy- 

 surus, the chief difference being the presence of internasals and the 

 consequent more lateral position of the nostrils. 



The genus, which is as yet but very poorly known, seems to contain 

 three species, the one here described, fi'om the Riu Kiu and Formosan 

 waters; E. chelonicephalus, from the Loyalty Islands; and E. annu- 

 latus, with single anal, and strongly tuberculated scales, from a 

 locality, probably somewhere in Australian waters. 



In discussing the specific characters of the species constituting the 

 genus Aipysurus, Doctor Guenther '' speaks of the head sliields being 

 much subdivided in old examples, impljdng that they are not so much 

 subdivided in the young. While our present species is not strictly 

 congeneric with those treated of by Doctor Guenther, it seems nearly 

 enough related to make it proper to question the above inference. I 

 have before me an adult female with two embryos ready to be ex- 

 pelled, and in all three the scutellation of the head is so identical that 

 the conclusion seems justified, that no change takes place as the snake 

 grows older, and that where a difference occurs it is due either to indi- 

 vidual or to specific variation. 



EMYDOCEPHALUS IJIM^Eo Stejneger. 



1898. EmydoccplmluH ijlmx Stejneger, Journ. Sci. Coll. Tokyo, XIII, Pt. 3, p. 223 



(typo-locality, Riu Kiu Sea; type, U.S.N.M. No. 36517; Tashiro, collector). 



1899. Aipysurus annulahts Boulenger, Zool. Record for 1898, Rept. Batr., p. 21 



(not of Krefft).— Wall, Proc. Zool. Soc. London, 1903, pp. 95, 101; 1905, 

 II, p. 517 (Okinawa). 



•'From £/<i3j, turtle; KS(pcxXy, head. 



ftRept. Brit. India, p. 357. 



c Named in honor of Pruf. I«io Ijima, Science College, Imperial Univerisily, Tokyo. 



