Jordan and Ever mann. Fishes of North America. 2061 



species ; 3 in front of spinons dorsal, 11 (or 12) along base of spinous dorsal, 

 2 (or 1) between dorsals, 6 at base of soft dorsal, 14 (or 13) unpaired 

 plates on back of caudal peduncle. The unpaired plates with the spine 

 notched at tip; all the plates marked with strong radiating ridges and 

 the surface of the spines minutely roughened. Color, light gray above, 

 white below; top and sides of head with black dots and dashes; back 

 crossed by six narrow black bars. Distinguished from all other species 

 of the genus by the great development of the lateral ridge and spines on 

 head. This gives the head and especially the snout a much broader outline, 

 approaching in this respect Agonus cataphractas. The species is repre- 

 sented by several young specimens in rather poor condition, the type 

 being 53 mm. long. The outline and armature of the head are not, how- 

 ever, essentially different in young and adults of such species as are 

 known to us from specimens of different sizes. Off Shana Hay, Iturup 

 Island, Kuril Group. (This species is named in honor of Prof. D'Arcy 

 Wentworth Thompson, of the University at Dundee, the commissioner of 

 Great Britain in the fur seal investigations in Bering Sea, in -1896 and 

 1897.) 



Podothecus thompsoni, JORDAN & GILBERT, Kept. Fur Seal Invest. 1806, 1897 MS., off 

 Shana Bay, Iturup Island, at Albatross Station 3653, in 18 fathoms. (Type, No. 

 5667, L. S. Jr. Univ. Mus. Coll. Albatross.) 



2413. PODOTHECUS ACIPENSERIMJS * (Tilesius). 

 (COMMON ALLIGATOR FISH.) 



B. T>; ID. 8 to 10; 2 D. 7 or 8; A. 7 or 8; P. 17 or 18; V. 3 (I, 2) ; C. 1-12-1; 

 vertebra- 12 -f 29 = 41. Pyloric cjeca 7 (2 individuals). Total length 

 reaches 10 inches. Body as deep as wide, ridges of dorso- and ventro- 

 lateral series strong, while those of the rest are but little developed, thus 

 giving body a sharply quadrangular form in front; dorsal and ventral 

 faces flat between ridges, the lateral convex. Behind middle of first dor- 

 sal the lateral ridges become more prominent and body more regularly 

 8-hedral ; tail 6-hedral, strongly depressed. The strong, curved, minutely 

 serrated spines of the dorsolateral series grow smaller from occiput back- 

 ward and disappear at beginning of second dorsal ; superior lateral series 

 spinous from middle of first dorsal to middle of peduncle; inferior lateral 

 series spinous for a short distance from a little in front of to a little behind 

 anal; ventrolateral series keeled, not spinous. Two pairs of plates 

 between last ray of second dorsal and first median plate, and 2 to 4 pairs 

 between last anal ray and first median plate. About 20 well-developed 



a 



pali 



to ' 



ba 



do 



uoiiiw} Dttrueia ax siues 01 lowerjaw. on OUT- wiin z pairs 01 spiiie, i p;m 

 zontally forward, the other curving backward and outward. One pair supraocular and 

 1 pair occipital spines. Color grayish brown, yellowish below ; sides with narrow undu- 

 lating vertical blackish streaks. 



