274 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, 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 gorgonse (Evermann & Goldsborough). 



Cheirodon gorgona 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 n; 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 gorgon* (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 



