ART. 20 NEW AND IMPERFECTLY KNOWN FISHES — GINSBURG 17 



posterior nostril with a raised margin, the rim in front being continued 

 into an expanded tiny flap fitting snugly over opening of nostril when 

 bent over. Barbule in front of eye at posterior edge of upper lip 

 small but very distinct. Tongue with a rather broad, V-shaped 

 emargination in front, continued into an abrupt narrow cleft of 

 medium depth, at mid line. Teeth in bands, those in outer row in 

 either jaw, especially those in upper jaw, conspicuously enlarged. 

 Base of ventral nearly under that of pectoral, tip of latter falling 

 short of a vertical through anus. Origin of first dorsal considerably 

 behind base of pectoral. Origin of second dorsal a little in advance 

 of the anal, end of base of latter under base of tenth dorsal ray; 

 posterior margins of both vertical fins free, not connected by mem- 

 brane to mid line. Body light brown with six lighter yellowish cross 

 bands, rather diffuse, not sharply differentiated. Fins without color 

 m«arks, plain yellowish. 



Measurements. — Total length, 44.2. Standard length, 36.4. Depth, 

 6 (16.5); least depth of caudal peduncle, 3.7 (10.2); length of head, 

 10.6 (29.1); depth of head behind eye, 4.3 (11.8); ventral, 6.7 (18.4); 

 distance ventral to anal origin, 12.2 (33.5) ; maxillary, 4.6 (12.6) ; 

 snout, 2.8 (7.7); eye, 2.5 (6.9); interorbital, 1.4 (3.8); postorbital 

 part of head, 6.5 (17.9) ; antedorsal distance, 14 (38.5) ; caudal, 8.2 

 (22.5). 



Holoiype.— U.S.N. M. No. 92801. Female. La Paz Harbor, Gulf 

 of California; March 12, 1889; Albatross. 



Remarks. — The present species is evidently closely related to Go- 

 hiosoma histrio Jordan but differs in the more slender caudal peduncle 

 and body, in having fewer fin rays, and in the color. 

 DiLEPiDiON, new subgenus 



Subgenotype. — Gobiosoma ginsburgi Hildebrand and Schroeder. 



Definition.' — This subgenus differs from typical Gobiosoma, as well 

 as from the subgenus Aruma, in having 2 ctenoid scales, and 2 only, 

 on the base of the caudal fin, 1 near the upper margin and 1 near the 

 lower. This character is very constant in many specimens of gins- 

 burgi examined and are conspicuous in fish as small as 22 mm in 

 standard length (the smallest examined) . The two scales are usually 

 firmly adherent, but sometimes one or more have fallen out, in which 

 case their pockets are readily discernible and are attached to the hind 

 margin of the caudal peduncle, one near the upper corner and one near 

 the lower. The subgenus Gerhardinus Meek and Hildebrand,^" like 

 Dilepidion, also has two ctenoid scales on the base of the caudal, but 

 the new subgenus differs in not having the mental frenum bilobed. 

 Besides the subgenotype, the following new species belongs to the 

 present subgenus. 



» Field Mus. Nat. Hist. Publ. Zool., vol. 15, pt. 3, p. 889, 1928. 



