GILBEET AND STAKES — FISHES OF PANAMA BAY 131 



Lips, gular membranes, and under side of snout naked, head and l)ody otherwise scaled. 

 Scales on mandible, and a small patch on base of anterior branchiostegals, cycloid; those in advance 

 of nostrils cycloid, or very «eakly ctenoid: scales otherwise strong^ly ctenoid. Second dorsal and 

 anal with a definite low scaly sheath at base, consistini>^ of a single series of small scales and in addition 

 series of scales on the membranes, extending two-thirds distance to tip. Caudal scaled to tip. Lateral 

 line with a long low curve, the height of which equals half diameter of orbit. 



Color steel-gray above, without dark streaks, white below, the cheeks and lower portion of 

 sides with much brown specking, sometimes confined to the margins of the scales. Mouth white 

 within. Lining of opercles blackish. Fins dusky, the distal part of ventrals black, the outer ray 

 white. Anal with the anterior rays tipped with black. 



A single specimen 187 mm. long. 



This species is closely related to 0. scierus, but differs in the longer, less 

 compressed bodjs the plain coloration, the turgid preorbitals, less arched lateral 

 line, and smaller canines. 



244. Ophioscion strabo Gilbert. 



This species is listed, without remark, by Boulenger (1899, p. 3) from Rio 

 Tuyra, and other rivers on the western slope of the Isthmus of Darien. The species 

 was not seen by us. These Panama specimens should be carefully compared with 

 the closely related species typicus and simulus, which are known from Panama and 

 closely resemble 0. strabo. 



245. Ophioscion imiceps {Jordan tC- Gilbert). 



This species seems to be rather rare at Panama. During our stay of six weeks 

 we secured twelve specimens. Like other species of the genus, 0. imicepti varies 

 greatly in length of snout and diameter of eye. 



Head 31- to 3| in length; depth 2« to 3|. Eye 4| to 54 in head; snout 3|- 

 to 4; interorbital width 3| to 4J; second dorsal spine 2| to 3; third dorsal spine 

 If to 2. 



246. Ophioscion scierus (Jordan <fc Gilbert). 



Plate XIX, Fig. 39. 



Common. 



The snout projects beyond the mouth for a distance varying from one-third to one-half 

 the diameter of the eye. It increases in sharpness with its length. 



Interorbital width (bone) 4J: to 4J in head (not 5^); snout 3i to 3^; eye 5^ to 5f. Gill- 

 rakers short, barely movable, 12 on horizontal limb of arch. Soft dorsal with a distinct, rather wide 

 sheath of scales at base; each interradial membrane with a series of scales, rapidly diminishing in size 

 from the base upward, reaching half way to margin of fin. Anal similarly scaled, the basal sheath less 



clearly defined. 



Second dorsal spine very stout, conspicuously stronger than any of the succeeding spines, all 

 of which are slender and weak. The eleventh spine is twice the length of the tenth. The second anal 

 spine is very robust, twice the width of the second dorsal spine, reaching to opposite the Up of the fifth 

 soft ray. Soft dorsal rays 24 or 25. 



Opercular lining blackish. 



