GILBEKT AND STAEKS— FISHES OF PANAMA BAY 133 



in the head. The low scaly sheath along the base of the soft dorsal disappears shortly before reaching 

 the end of the fin. The second anal spine is nearly or quite equal to the length of the snout. Pec- 

 torals extending well beyond the ventrals, 1 3 in the head. Outer ventral ray filamentous, if in head. 

 Caudal with the middle rays longest, the outline of the fin concave above the middle, convex below it. 



Scales above the lateral line in very oblique series downward and backward, normally 40 or 41 

 in number; in one specimen there were but 35 rows, in another 43. An occasional scale is intercalated 

 between these series as they approach the lateral line, the number of pores slightly exceeding the 

 series. 



Color as usual in the genus. Upper part of axil dusky. Opercular lining dusky, becoming 

 black posteriorly, where it contrasts strongly with the silvery opercular membrane. 



This is a common species at Panama. Our description is based on specimens 

 31 to 36 cm. long. 



250. Umbrina xanti Gill. 



Recorded from Panama by Giintber (1868, p. 426, as U. analis), and by 

 Gilbert. Not seen by us. 



251. Umbrina dorsalis Gill. 



Infrequent; four specimens secured. , 



Dorsal X, I, 29, 29, 31, 31. Anal II, 7, 7, 7, 8. Eye 4^ to 4| in head; 

 snout 3| or 3|. Preopercular margin scarcely serrate, provided with a rather thick 

 membranous border with small flexible teeth. 



252. Menticirrus nasus (Giinther). 



Mcnticirrus simus Jordan & Eigenmann, 1889, p. 437. 



Frequent in the Panama market. The twelve specimens before us differ 

 in the size of the eye and the form of the snout sufficiently to demonstrate the 

 identity of M. simus and M. nasus, which have been separated on differences similar 

 to those here found. 



Head 3:|- to 3^ in length; depth 4|- to 4|. Eye equals snout in front of ante- 

 rior nostril, and is contained 5f to 5^ in head; snout 3f to 34^. The third dorsal 

 spine is the longest and is contained 4] to 4f in the length. When the fin is 

 depressed, its tip reaches variously from the base of the first ray of the second dorsal 

 to the base of the fourth. Above the lateral line, there are 50 oblique series of scales 

 running downward and backward. 



The nostrils are larger than in M. j^ftnamensis, the anterior nostril round or 

 very slightly oval, distant half its diameter from the posterior nostril. A dermal 

 flap is attached to its posterior edge, and extends back to the posterior nostril. The 

 posterior nostril varies in shape from widely to narrowly elliptical. Its posterior end 

 is usually pointed and reaches the beginning of the adipose eyelid. 



The caudal is S-shajied; its upper angulated lobe extends beyond the lower 

 rounded lobe a distance equal to the diameter of the eye. 



( 18 ) December 12, 1903. 



