148 CALIFORNIA ACADEMY OF SCIENCES. 



the latter, based on current descriptions, have been at- 

 tempted by Gill, and by Jordan and Gilbert. 



A tine alcoholic specimen of this species is in the pos- 

 session' of the California Academy of Sciences, to which it 

 was presented about 1882 by Dr. Krause of Berlin, Ger- 

 many. This has been kindly loaned to the writer, and 

 on it are based the following figures and descriptions. 

 The specimen is 360 mm. long, and was obtained in the 

 Okhotsk Sea. 



Ilippocephaliis japonicus is most closely related to Agon- 

 omahis prohoscidalis and Hypsagonus qnadricoriiis. These 

 three species are confined to the shores of the North Pa- 

 cific Ocean and differ much more from the other mem- 

 bers of the family than they do from each other. The 

 group is distinguished by having the body compressed, 

 the back elevated behind the nape, two rows of strong 

 spines along each side of body, the spinous dorsal begin- 

 ning immediately behind the nape with its spines strong 

 and rough, the mouth terminal, and the branchiostegal 

 membranes broadly united and free from the isthmus. 



The genus Hippoccphalus may be defined as fol- 

 lows: Body moderately elongate, compressed, the back 

 elevated behind nape ; two rows of strong spines along 

 each side of body ; spinous dorsal beginning immediatel}' 

 behind nape, the spines strong and rough; head depressed; 

 gill -membranes free from the isthmus; mouth terminal; 

 teeth present on jaws and vomer, none on palatines; no 

 barbel at tip of snout; no occipital spines; the two dor- 

 sals well separated. 



SYNONOMY. 



Cottus ja})onkus Pallas, "Spicilegia Zoologia, vii, 30, plate v, figs. 1-3, 

 1772," dry specimen, Kurile Islands; Gmeliu, Syst. Nat. Ed. XIII, 

 p. 1213, 1788 (after Pallas); Walbaum, Artedi's Ichtbyologia, Part 

 iii, 387, 1792; Tilesius, "Krusenstern's Keise urn die Welt, iv, plate 

 87, 1813." 



Phdlarujisiex japonicHs Pallas, Zoog. Rosso-Asiat., iii, 112, 1811. 



