Family XIV. Atherinid^e. 183 



68. Melaniris Meek. 



Melaniris Meek, Field Col. Mus. Pub. 65,1 89 2, 117. (Type, Melaniris 

 balsanus Meek.) 



Body elongate, slender; lower jaw rounded; origin of spinous dorsal 

 fin behind that of the anal; caudal peduncle short; peritoneum black; 

 alimentary canal shorter than total length of the fish ; iris black ; ver- 

 tebrae 17 + 19 = 36. 



173. Melaniris balsanus Meek. 



Melaniris balsanus Meek, Field Col. Mus. Pub. 65, 1902, 117; 



Balsas. 

 Basin of the Rio Balsas; not taken above the falls and cascades. 





Fig. 64. Melaniris balsanus Meek. 



No. 370b, Field Columbian Museum. 



Head 4^3; depth 5^; D- ni-9; A. 21; scales 10-39. Body elon- 

 gate, slender, not much compressed; snout rounded laterally; mouth 

 small, lower jaw slightly the longer; outer row of teeth large, canine - 

 like, wide apart, behind these a band of small villiform teeth; gill 

 rakers 4+13 = 17; vertebras 17-1-19 = 36; scales large, with entire mar- 

 gins; caudal peduncle very short; -'dorsal fins posterior; origin of 

 spinous dorsal considerably behind origin of anal fin, and midway 

 between base of caudal fin and posterior margin of opercle ; base of 

 anal % longer than head, its rays varying from 20 to 23; dorsal 

 spines 2 to 4, usually 3 ; pectoral fin high on sides of body, its length 

 i^in head; ventrals 2 %. 



Color olivaceous, rather opaque, dorsal region finely punctulate 

 with black; a well defined silvery band on sides. Length about 3 

 inches. 



This species is very abundant in the Rio Cocula and the Rio Balsas 

 at Balsas. It has not been taken elsewhere. It probably spawns in 

 Mav. 



