Jordan and Evermann. Fishes of North America. 793 



This genus is distinguished from Basilichthys and Menidia by the very 

 long and strong mandible, which protrudes beyond the upper jaw. The 

 scales are small, the teeth well developed, there are usually a few vomerine 

 teeth, and the premaxillary is extremely protractile. The known species 

 inhabit Mexico and Brazil, (^ap, hand ; aro^a, mouth, from the protrac- 

 tile mouth.) 



a. Scales 42 to 50 in longitudinal series; a patch of teeth on vomer. 



b. Anal rays 1, 19 or 20; head more than % length. HUMBOLDTIANUM, 1155. 



66. Anal rays I, 15 or 16; head less than^ length. BARTONI, 1156. 



aa. Scale larger, 35 to 37; teeth very weak, none on vomer. JORDANI, 1157. 



1155. CHIROSTOMA HUMBOLDTIANUM (Cuvier & Valenciennes). 



Head 4 in total length ; body slender, 5 in total length ; eye 6 in head, 2 

 in snout. D. V-I, 10 or 11 ; A. I, 19 or 20 ; scales 50, their edges entire. 

 Pectoral short, broad, pointed, 7 in total length. First dorsal over tip 

 of ventral, which is f length of pectoral ; second .dorsal over middle of 

 anal. (Cuvier & Valenciennes.) Two specimens from a lake near the 

 city of Mexico, respectively 11 and 8 inches in length, the types of hum- 

 boldtwnum and vomerinum. The type of vomerinum is said to have slight 

 tooth-like asperities on the vomer. Not seen by us. (Named for Alexan- 

 der von Humboldt, 1769-1859, the famous author of " Cosmos,-' who col- 

 lected fishes in South America and Mexico.) 



Atherina humbotdtiana, CCVIER & VALENCIENNES, Hist. Nat. Poise., x, 479, 1835, lake near 



City of Mexico. 



Atherina vomerina, CUVIER & VALENCIENNES, I. c., 481, lake near City of Mexico. 

 Atherinichlhys humboldti, GUNTHER, Cat., in, 404, 1861; after CUVIEE & VALENCIENNES. 



1156. CHIROSTOMA BARTONI, Jordan & Evermann, new species. 



Head 4 ; depth 6 ; eye 4 ; snout 3J. D. IV-I, 10 ; A. 1, 15 ; scales 42-10, 

 large and loose, and with entire edges ; about 24 scales before the dorsal. 

 Origin of spinous dorsal midway between insertion of ventrals and 

 origin of anal, midway between tip of snout and base of caudal fin. 

 Mouth large, the mandible If times the large eye, the premaxillaries very 

 protractile. Teeth well developed on jaws and vomer. Color silvery or 

 straw color ; a narrow plumbeous lateral band, edged above with black, 

 along middle of side, indistinct anteriorly but well marked in posterior 

 f of its course ; rest of body with scattered brownish punctulations. 

 Length 3| inches. Only one specimen known (Type, No. 23136), from a 

 tributary of the Rio Lerma, near Guanajuato, Mexico, where it was 

 obtained by Prof. Alfredo Duges. (Named for Mr. Barton A. Bean, Assis- 

 tant Curator of Fishes in the United States National Museum.) 



Chirostoma humboldtianum, JORDAN, Proc. U. S. Nat. Mus., 1879, 299; not of CUVIER & VALEN- 

 CIENNES. 



1157. CHIROSTOMA JORDANI, Woolman. 



Head 4 ; depth 4f . D. IV-I, 8 or 9 ; A. I, 6 ; scales 35 to 37. Body 

 elongate, slender, compressed; belly not compressed; head medium, 



