674 PROP. R. COLLETT ON A NEW AGONOID PISH. [NoV. 20, 



Locality. — Kamtschatka. In 1879 the museum of Christiania 

 received from Consul Henry Lund in San Francisco a small 

 collection of fishes and marine invertebrates, collected by a 

 Norwegian sailor at Kamtschatka. Amongst the first were 12 

 specimens of this species, some of which were rather defective and 

 in a bad state of preservation. All except one were full-grown 

 specimens. The exact locality was not given. 



Kemabks. — A. gilberti is allied to A. (Podoiliecus) adpenseriiius, 

 Tiles. 1810, but differs from that species in several characters, 

 viz. : — 



The more elongated body. In A. gilberti the end of the 2nd 

 dorsal is midway between the caudal and the middle of 1st dorsal ; 

 in A. acipenserinus between the caudal and the beginning of the 

 1st dorsal. 



The more compressed body. Prom head to caudal everywhere 

 higlier than broad ; in A. acipenserinus much broader than high. 



The longer snout. The interorbital space is contained 3 times 

 in the length of the snout ; in A. acipenserinus a little more than 

 twice. 



Dorsals more separated ; interdorsal space with 3 or 4 plates, 

 in A. acipenserinus only 1 plate (sometimes 2), or the fins almost 

 contiguous. 



Ventral groove present in A. gilberti, absent in A. adpeiiserinv^. 

 Colour with distinct stripes on head and spots on body ; in A. 

 acipenserinus cross-bars on the body, the head being almost 

 unspotted. 



The other species of the same subgenus, A. (PodotJiecus) valsus, 

 Jord. and Gilb. 1880, has the body everywhere broader than high. 

 The spines of the head are more numerous (more than 70 spines 

 and tubercles on the head) ; there is a deep quadrangular pit on 

 the occiput ; no barbels on lower side of snout ; the 1st dorsal 

 commences behind the seventh dorsal plate, and the fin-formula is 

 different. 



The genus Podothecus was established by Grill in 1861 ^ for a 

 species called P. peristethus, which is commonly believed to have 

 been based on a badly-preserved specimen of A. acipenserinus. 

 But it must be borne in mind that one of the characters of the said 

 genus (the very one from which the name is derived), " ventral fins 

 received in a long lanceolate groove," is not shown by A. acipen- 

 serinus. 



As other essential characters of the genus are mentioned " the 

 longer spinous dorsal and the greater number of plates on the 

 breast." ^ None of these characters, however, are of sufficient 

 importance to justify the establishment of a new genus. 



As another character for Pocbthecus, Jordan and Gilbert state ^ 



1 Proc. Acad. Nat. Sci. Philad. 1861, p. 258. 

 =• Proc. U.S. Nat. Mus. vol. iii. 1880, p. 332. 



' " Synopsis of the Fishes of North America" (Bull. U.S. Nat. Mus. no. 16, 

 p. 714, Wash. 1882). 



