GILBERT AND STARKS — FISHES OF PANAMA BAY 



41 



74. Opisthopterus dovii {Giinther). 



This species is known only from Panama, where it occurs but rarely. Four 

 specimens were seen, 18 to 20 cm. long; they agree well with Giinther's diagnosis. 

 Head 41 to 5 in length; depth 3i to 3i. Eye 31 to 31 in head; maxillary 1t% or 2. 

 Pectorals long, pointed, 4 to 4f in length. Origin of dorsal neai-er caudal than 

 scapula by half length of head. A. 55, 59, 61, 62 in our specimens; D. 11, 12, 13, 

 14. Scutes 27 or 28. Teeth in jaws strong, incurved, in a single series. 



Color light olivaceous above, bright silvery below angle of gill-opening. A 

 faint bluish streak sometimes present along upper edge of silvery area. No dark 

 humeral spot. A broad black vertebral band. End of snout and tip of lower jaw 

 black. Fins translucent, with dark specks along the rays. 



75. Opisthopterus macrops {Giinther) . 



Occurring but rarely. Three specimens were obtained, each about 225 mm. 

 long. 



The species is readily distinguished from 0. dovii by its much larger eye, 

 more oblique mouth, strongly concave occipital 2:)rofile, and deeper body with much 

 stronger ventral curvature. The teeth are much smaller than in 0. dovii, and there 

 is a conspicuous humeral spot, lacking in the latter. In the specimens taken, the 

 head is 41 or 41 in length, the depth 21 to 3. Eye 21 to 21 in head. Front of dorsal 

 slightly nearer root of caudal than scapula, farther forward than in 0. dovii. Pec- 

 toral 41 to 41 in length. Scutes 27. D. 13 or 14. A. 62. Coloration as in 0. dovii, 

 but with a large black humeral spot. 



Not heretofore reported since the discovery of the type at Panama by Capt. 

 J. M. Dow. 



76. Odontognathus panamensis (Sieindachner). 

 Only the type specimen is known. 



