HYNOBIIDAE. 469 



* 



and //. retardatus. I have seen no specimen of cristatus but it seems 

 to be more allied to keyserlingii, on account of the dentition, the costal 

 groove count, and the feet, which are the same as those of the Siberian 

 form and very different from those of the Yezo animal. On the other 

 hand the tail is quite like that of retardatus. But the Yezo species 

 seems to me to be an end form, very specialized, derived from peropus 

 of Hondo, and while the matter cannot be regarded as settled, it is 

 far more probable, both anatomically and geographically to regard 

 cristatus as derived from keyserlingii, from which it differs, as Anders- 

 son says " very clearly in the structure of the tail, which is higher, 

 longer, more compressed, and crested; also the colour is quite dis- 

 similar. In addition to this the vent has a triangular flap, the limbs 

 are longer, and the body shorter in proportion to the head." 



Nikolski's reference (1905) to a specimen of keyserlingii in the 

 Petrograd museum from Sakhalin (No. 1941, collected by Dr. Sapru- 

 nenko in 1890), probably refers in reality to cristatus. 



Hynobius peropus Boulenger. 



1882. Hynobius nebuiosus Boulenger (part ?), Cat. Batr. Grad. Brit. Mus. (2), 

 p. 32; Okada 1891, Cat. Vert, Japan, p. 65; Stejneger 1907, Bull. 

 U. S. Nat. Mus. 58, p. 30, ff. 23-26; Sternfeld, 1916, S. B. Ges. 

 Nat. Fr. Berlin, p. 172; Abe 1921, Tokyo Zool. Mag., p. 330. 



1882. Hynobius peropus Boulenger, loc. cit,, p. 33, pi. 2, f. 1; Stejneger, 



loc. cit., p. 32, pi. 4, ff. 4-7; Tago, 1907, Tokyo Zool. Mag. 19, 

 p. 202; Hashimoto, 1910, Tokyo Zool. Mag., 22, p. 497. 



1883. Hynobius lichenatus Boulenger, Ann. Mag. Nat. Hist., (5), 12, p. 165, 



pi. 5, f. 1, (Aomori, Mottsu Prov.); Stejneger loc. cit., p. 36, pi. 4, 



ff. 1-3; Tago, loc. cit., p. 203; Hashimoto, loc. cit., p. 497. 

 1907. (July 22) Hynobius nigrescens Stejneger, loc. cit,, p. 34, ff. 27-32 



(Sendai, Rikuzen Prov.); Tago, loc. cit., p. 204; Hashimoto, 



loc. cit., p. 497; Abe, loc. cit., p. 330. 

 1907. ("July") Hynobius fuscus Tago, loc. cit., p. 204, 233, (Nikko, Shimo- 



zuke Prov.); Hashimoto, loc. cit,, p. 499. 

 1921. Hynobius naevius Abe (part?), loc. cit,, p. 329. 



Type: In British Museum. Adult male, collected by Mr. A. 

 Adams. 



Type Locality: "China or Japan." 



Range: From northern extremity of Hondo to the Provinces of 

 Izu and Yamato. 



Diagnosis : A Hynobius with thick tail, which may be keeled above; 



