92 BULLETIN 150, TJ^TITED STATES NATIONAL MUSEUM 



The genus Polypera differs from Liparis solely in the number of 

 pyloric coeca. None of the 30 species of the latter genus has as 

 many as 100 pyloric coeca. The pyloric coeca in Polypera are 

 matted closely together and can be distinguished without counting 

 from those of any of the species of Liparis. The dentition in Poly- 

 pera is distinct from that found in any of the species of Liparis in 

 which the dorsal fin is notched. The larger teeth in Polypera greeni 

 are simple or have the lateral lobes but faintly indicated. The 

 nearest approach to this type of dentition found amoung the species 

 of Liparis is in Liparis major (Gill). In the latter species some of 

 the larger teeth are simple, but in other characters the species is so 

 widely divergent from Polypera greeni that we are led to beheve 

 that the similarity in dentition is due to parallel development. 



KEY TO SPECIES OF POLYPERA 



A*. Dorsal 40 or less; anal 30 or less; pectoral 37. 



B'. Color pale gray; gill opening above the pectoral or in front of the upper ray. 



P. beringianus. 

 B^. Color light brown with the epidermis removed; gill slit either above the 



pectoral or in front of one to four rays P- greeni. 



A*. Dorsal 44; anal 34; pectoral 40 P- simushirae. 



POLYPERA GREENI (Jordan and Starks) 



Neoliparis greeni Jordan and Starks, 1895, p. 829, pi. 96. — Jordan and Ever- 



MANN, 1898, p. 2112, fig. 763. 

 lAparis tunicatus Bean and Bean, 1896a, p. 243. 

 Liparis callyodon Bean and Bean, 1896a, p. 243 (part, No. 47561). 

 Liparis hercshelinus Jordan and Gilbert, 1899, p. 476 (part.). 



TV^e.— Female, No. 3019, S. U. Z. M. Victoria Harbor, British 

 Columbia. Length 244 mm. 



Distribution. — Apparently extending northward from British Co- 

 lumbia to the Aleutian Islands. The specimen from Bering Island 

 appears to belong to this species. Depth unknown; the type was 

 dredged in Victoria Harbor, and the records of the Bering Island 

 specimens are incomplete. Four specimens examined. 



Relationships. — The three species of Polypero recognized in this 

 work appear to be very closely allied and I am not certain that all 

 three species should be recognized. More material must be obtained 

 before we can demonstrate the validity of all three species. P. 

 simushirae is based upon a single specimen. The horizontal dis- 

 tribution of P. greeni and P. beringianus is practically identical; 

 it is possible that the vertical distribution of the two species may differ. 

 P. greeni appears to come from deeper water than either P. beringia- 

 nus or P. simushirae. As P. beringianus is known only from small 

 specimens it is possible that it may represent the young of either 

 of the other species. We will indicate here the apparent differences 

 between the three species. P. beringianus has a paler coloration and 



