GILBEET AND STARKS — FISHES OF PANAMA BAY 



201 



of dorsal and anal fins respectively. In older sj^eciraens, the cilia are less numerous, 

 and usually disappear entirely in adults. 



As in A. ina?.atlanns, the lower two-thirds of the opercle, as well as the sub- 

 opercle and the preopercle on the blind side are naked; in A. kliinzingeri, the scales 

 on cheeks and upper part of opercles are non-imbricate and frequently smooth, 

 especially in specimens of large size. 



The eyes are small and distant, the interocular space usually wider than the 

 diameter of the eye. The pectoral varies widely in length and in the number of 

 rays, seven specimens showing respectively 5, 5, 4, 4, 4, 3 and 2 pectoral rays. In 

 five specimens there are 71 to 76 oblique rows of scales running downward and 

 backward to the lateral line. In five specimens of A. mazatlanns, there are 54 to 61 

 oblique rows. In three specimens of A. klunzingeri, there are 62 to 64 dorsal rays, 

 46 to 49 anal rays; in four specimens of ^1. mazatlamts, 52 to 55 dorsal rays, 40 to 43 

 anal rays. 



Measurements in Hundredths of Length without Caudal. 



Length to base of caudal in mm 



Head 



Snout 



Maxillary 



Eye 



Interorbital width 



Depth 



Depth of caudal peduncle 



Length of caudal fin 



Length of pectoral 



Longest dorsal ray 



Longest anal ray 



i6o 



27 



loi 



64 

 20 

 30 



4 



14A 

 15 



365. Achirus fonsecensis {Gilnther). 



Solea fonsecensis Gunther, 1862, p. 475 (Gulf of Fonseca). 



Solea fischeri Steindachner, 1S79 r, p. 13, PI. II, fig. 8 (Rio Mamoni, near Panama). 



Solea pananiensis Steindachner, 1877, p. 10, PL II (Panama). 



This species is abundant in the Bay of Panama and appears frequently in the 

 market. It has not been recorded south of this point, but extends to the northward 

 as far as Mazatlan. 



The pectoral fin is greatly reduced, containing usually two short divergent 

 rays, which fail to equal the diameter of the orbit. In one of our specimens three 



