2 74 Field Museum of Natural History — Zo5logy, Vol. X. 



This genus differs from Cheirodon in the peculiar scaling on the 

 lower half of the base of the caudal fin of the male, and also in the 

 non-projecting interhaemal spines of the caudal peduncle. 



25. Compsura gorgonae (Evermann & Goldsborough). 



Cheirodon gorgonm Evermann & Goldsborough, Proc. Biol. Soc. Wash., 



XXII, 1909, 99, figs. I and 3 (Gorgona, Atlantic slope, Panama 



Canal Zone). 

 Cheirodon insignis Eigenmann, Memoir. Carnegie Mus., VII, 1916, 69 



(in part) . 



Head 3.7 to 4.25; depth 2.55 to 3.3; D, 10 or 11; A. 16 to 20; scales 

 31 to 33. 



Body rather short, compressed; profile gently convex from snout to 

 dorsal; head small; snout short, 4.1 to 5.4 in head; eye 2.6 to 3.25; 

 interorbital 3.1 to 3.6; mouth small; jaws subequal; maxillary reaching 

 anterior margin of eye; premaxillary teeth usually 10 in number, each 

 tooth with about 6 cusps, the median cusps considerably enlarged; 



Fig. 2. Front teeth of Compsura gorgoms (Evermann & Goldsborough). 

 (After Evermann & Goldsborough.) 



maxillary usually with 2 teeth, similar to the premaxillary teeth; teeth 

 in lower jaw usually 12 in number, close together, the expanded tips 

 slightly overlapping, each with about 6 cusps, the median ones only 

 slightly enlarged, making the margin evenly convex; lateral line in- 

 complete, present on 5 to 13 scales; scales thin, striate, 10 to 12 in 

 advance of dorsal; 8 to 10 rows between dorsal and adipose; dorsal fin 

 pointed, the anterior rays the longest, its origin midway between tip of 

 snout and base of caudal; adipose fin over last ray of anal, notably 

 nearer base of caudal than dorsal fin; caudal fin naked, the lower lobe 

 the longer; origin of anal under last rays of dorsal, its base considerably 

 shorter than depth of body; ventral fins inserted a little in advance 

 of dorsal, reaching nearly or quite to origin of anal; pectoral fins some- 

 what longer than ventrals, usually not quite reaching the base of the 

 latter. 



Color silvery, with a narrow plumbeous band; a very conspicuous 

 black oval caudal spot, not extended on caudal rays. Head and body 



