ElGENMANN : THE EXPEDITION TO BRITISH GUIANA. 39 



Pectorals with the tips of the outer rays thickened, reaching ventrals ; 

 ventrals not to anal ; highest anal ray a little less than the length of 

 the caudal peduncle, reaching a little beyond tip of the last ray, but 

 not to caudal fulcra ; base of dorsal fin reaching over half way to the 

 adipose, 6 in the length, the third ray extending about halfway to tip 

 of last. 



Straw-color ; a narrow black band from tip of snout to base of 

 middle caudal rays, where it ends near a small black spot ; about 

 ten brown cross-bands, the fifth encircling the entire body at tips^-of 

 ventrals, in the type, sometimes they become double along the sides, 

 giving the appearance of many narrow bands. Back dusky, the centers 

 of the scales light. Opercle and lower lip dark. Ventral surface 

 colorless. Dorsal with a spot behind and near the base of each ray, 

 beginning with the fourth ; chromatophores along the branched part of 

 the rays ; other fins hyaline, without distinct markings. 



Characidium pellucidum sp. nov. 



Type, 39 mm. (No. 1156 Carnegie Museum Catalog of Fishes.) 

 Gluck Island. 



Cotype, 37 mm. Gluck Island. (I. U. Cat. No. 11683.) 



Resembling Ammocrypta pellucida. 



Head 4.33 ; depth 7 ; D. 11; A. 8 ; scales 3-36-2, nine in front 

 of dorsal. Eye a little longer than snout, 3.75 in head; bony inter- 

 orbital a little less than half length of head. Teeth with three large 

 points. 



Pectorals reaching ventrals, its outer rays not thickened ; ventrals 

 not to anal; anal rounded, the third ray reaching a little beyond tip 

 of last, but not nearly to caudal ; dorsal truncate, the third ray reach- 

 ing a little beyond middle of last ; base of dorsal 6^ in the length, 

 equal to one-half its, distance from tip of adipose. 



Pellucid in life. Middle of sides with 27-30 stellate chromato- 

 phores, one or more of which may have slipped up or down from the 

 line of the rest ; a few smaller cells dorsad of the lateral series ; back 

 with about sixteen cross-bars, which do not encroach on the sides. A 

 dark band forward from eye to end of snout. Upper part of cheek and 

 opercle each with a chromatophore ; top of head with a few chromato- 

 phores ; ventral parts clear except a patch of chromatophores between 

 the pectorals, one between the ventrals and a patch at origin of anal ; 

 a dark median line between tip of ventral and another behind the anal 



