A REVIEW OF EAST ASIAN PYGOSTEIJS—BERG. 



453 



PYGOSTEUS SINENSIS STENURUS (Kessler). 



Lladerosteui< denurus Kessleu in Przewalski, ]Monj,ailia, and the land of Tanguts, 

 1876, Fishes, p. 6, pi. iii, fig. 6 (Dalai-nor, 43° N. ). 



We have specimens from Lake Dalai-nor in E. Mongolia (No. 2471 

 type-specimens) which differ from P. sinensis in having a more slender 

 ))ody. The depth of the body is contained (3 times in the total length 

 without caudal, while in sinensis 5-5^. The lateral armature is usually 

 but little developed, the shields being small. 



PYGOSTEUS SINENSIS WOSSNESSENSKYI (Kessler). 



Uasterosteus wossnessenshyi Kessler, in Przewalski, Mongolia, and the land of Tan- 

 guts, 1876, p. 9 (west coast of Kamchatka; Nos. 2377-8). 



We have specimens from Kamchatka (No. 2377-8 coll., Wossness- 

 ensk}"). The lateral armature is nuich less developed, even in the 

 anterior part of body frequently wanting. Length to 90 mm. 



Name and lociilitv. 



l'!/(/ostei(s pitngitinf. 



Onega L. (N. Russia) 



Hakodate 



Ajan (Sea of Okhotsk) 



Alaska , 



P. sinensis. 



Khanka L. (Amur R. ) 



Vladivostok , 



Ussuri R 



Sungari R 



Hakodate , 



P. sine7isis stenurus. 



Dalai-nor (Mongolia) 



P. sinensis icossnessenskyi 



Kamchatka 



P. Iymc7isis. 

 Sakhalin 



X 



IX 

 XI 



XI 



IX 

 IX 

 IX 

 VIII 

 IX 



IX 



IX 



taCO 



IX 

 IX 



3.6 

 3.7 



3.8 

 4.3 



4.4 

 4.7 

 3.6 

 4.0 



3.7 



3.9 



4.1 



3.7 

 4.1 



3.5 



5a 



E-a 



csi 

 (> tic 



■t,si 

 c a 



2.33 

 2.33 

 2.33 

 3.01 



2.01 

 2.01 

 1.74 

 1.88 

 2.52 



2.80 

 2.18 



2.96 

 3.16 



The following is a .synopsis of the known Eurasiatic species of 



Pygosteus: 



a. Caudal peduncle laterally with a well developed keel. 

 b. Anterior j^art of body naked, without bony plates. 

 c. Lateral [exterior, upper] processes of the pubic bone well developed, ventral 

 spine long, l|-3in head; dorsal spines high. Circumpolar P. pimgitius. 



