GILBERT AND ST ARKS — FISHES OF PANAMA BAY 115 



213. Gerres peruvianus Cuvier <.(; Valenciennes. 



We found this species very common at Panuniii. From G. olisthostomus it 

 iliffers in having the preniaxiUary groove scaleless, a smaller eye, smaller and 

 crowded teeth, and a higher sheath of scales to dorsal and anal. From G. aureolus 

 (as described) it differs in having the eye not larger than length of snout or width 

 of interorbital, and in having the second dorsal spine much stronger than the others, 

 and much more than half length of head (second dorsal spine of G. peruvianus is 

 from 1^^ to 11 in head). 



214. Gerres brevimanus Gmither. 



Probably not common; we collected five specimens ranging in entire length 

 from 23 to 36 cm. The species may be at once distinguished from all other Amer- 

 ican sjiecies by the short pectoral, which never reaches the vertical from the vent, 

 and which equals in length the post-nasal part of the head. 



The lips are much thickened, especially the lower one. In the smaller 

 specimen the breadth of the lower lip at its widest part is contained 3| times in the 

 diameter of the eye. In the largest one, it is contained 2^. Between these there is 

 a regular gradation, with the exception of the next to the largest specimen (31 cm. 

 long), in which the lips are much wider than in any other. In this, the lower lips 

 are thickened until they meet on the median line, and appear as a medially divided 

 flap, which extends backward to below the corners of the mouth, where it is trun- 

 cated. We cannot determine whether this is a sexual character, as our specimens 

 unfortunately have been eviscerated. 



The upper profile of the head is concave above the eyes and convex above 

 the nostrils; the snout is blunt, in the large specimens projecting beyond the tip of 

 the lower jaw a third of the diameter of the eye, in the small specimens somewhat 

 less. The eye varies much with the size of the fish and is contained (inside of tlie 

 adipose eyelid) from 3i to 4.1 times in the length of the head. Its width nearly 

 equals the length of the snout in the smallest specimens; in the largest ones it is 

 contained from li to 1| times in the snout. 



The gill-rakers are very short, 9+13 in number. The exposed portion of 

 the maxillary varies in length from 4] to if in the length of the head. The ventral 

 spine is stout and blunt, about six-tenths of the longest ventral ray. The second 

 anal spine does not project beyond the third, which about equals the soft rays. The 

 third dorsal spine projects beyond the second, sometimes beyond the fourth. 



The streaks along the rows of scales are scarcely fainter than in G. lineatus; 

 those above the lateral line are as conspicuous as those below. 



Giinther's statement that the length of the head is twice and a half in the 

 length of the body is evidently a misprint. It should read thrice and a half. 



