46 Annals of the Carnegie Museum. 



shorter than snout, 3.3 in the head, equal to the interorbital. Upper 

 jaw projecting. 



Dorsal inserted slightly behind the vertical from the insertion of the 

 ventrals ; pectorals reaching half way to second third of ventrals ; ven- 

 trals half way to base of last anal ray ; adipose fin over middle of last 

 anal ray. 



Light brown above, bordered below by a black band from tip of 

 snout and mandible to the end of the lower caudal lobe ; the band is 

 widest on the caudal peduncle where it unites with its fellow of the 

 other side ; a bar connects the two lateral bands in front of the anal. 

 Lower parts silvery-white. Dorsal hyaline ; lower caudal lobe black, 

 obliquely crossed near the center by a red band, and margined with 

 red above ; usually a black, ocellus-like spot or streak near the middle 

 of the caudal rays near the center of the fin ; middle, and sometimes 

 the posterior anal rays, dark. Opercle purple. 



Archicheir gen. no v. 



This genus is a Nannostomus with peculiar pectorals. In Nanno- 

 stomus the pectorals are normal, as in related genera ; in this genus 

 they appear to have retained the embryonic structure. They are 

 broad, dermal flaps, with hair-like fringes. 



Gill-membranes united, free from the isthmus. 



Archicheir minutus sp. no v. 



Type unique, 26 mm. (No. 1186, Carnegie Museum Catalog of 

 Fishes. ) Canal at Christianburg. 



This species is readily recognizable by the color of the caudal and 

 anal fins. 



Head 3.5; depth 5.66; D. 9 ; A. 11; scales large. Eye 3.5 in 

 the head, considerably greater than the interorbital, but little shorter 

 than the snout. 



Origin of dorsal a little posterior to origin of ventrals. 



Adipose fin considerably behind tip of the anal. 



Back chocolate. A light band from end of snout to base of superior 

 caudal lobe ; a dark band from end of maxillary to the base of the 

 inferior caudal lobe. A black spot at base of the pectoral and one 

 before the first ventral ray. Dorsal dusky ; adipose black. Middle 

 caudal rays black ; an oblique bar from the edge of base of each lobe 

 to the end of the median black bar, the lowermost one much the 



