6 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY—II. 
entirely naked; body entirely naked, except the caudal peduncle, which is 
sparsely covered with thin, imbedded scales, and a series of rather large 
scales along the sides, on which the lateral line runs; upper jaw some- 
what protractile; mouth rather wide, nearly terminal; a single anal 
spine. The name Ammocrypta is given in allusion to the habit of hiding 
in the sand, which is characteristic of the species of this genus and 
Pleurolepis. 
Specific characters —General form of Plewrolepis pellucidus, but the 
head heavier. Depth about 6 in length (to base of caudal—as in all 
cases in this paper); head 32; mouth large, the upper jaw rather 
longest, and somewhat protractile ; cheeks and opercles entirely naked. 
A series of rather large scales, about 65 in number, forming the lateral 
line; a few scattering scales immediately above or below lateral line; 
behind anal and second dorsal, the caudal peduncle is covered with 
small, thin, imbedded scales. 
Fin rays: Dorsal X—10. Anal I, 9. The two dorsal fins very high, 
wide apart, about equal to each other and to the large anal. Caudal 
fin emarginate. 
Color clear translucent, without bars or spots, the lateral line shining- 
golden in life (Bean). Spinous dorsal fin with a large black spot on the 
membrane anteriorly, another near the middle, and some small ones be- 
hind; otber fins with their membranes dusted with small punctulations, 
Habitat.—Notalbany River, near Tickfaw, La. Collected in Decem- 
ber, 1876, by Dr. Tarleton H. Bean, of the Smithsonian Institution, for 
whom the species is named. The type—about 24 inches in length—is 
in the United States National Museum. 
The much greater height of the dorsal and anal fins, as well as the 
generic character of the naked body, distinguish this species from its 
sand-diving relatives, Plewrolepis pellucidus and P. vitreus. 
3. NANOSTOMA, Putnam, MSS., gen. nov. 
The name of Nanostoma, a manuscript genus of Darters, has been 
current in ichthyological circles for some time, and it has once or twice 
appeared in print, but no attempt has ever been made to characterize 
it. 1 find in the National Museum two species of Etheostomoid 
fishes, labelled by Prof. Putnam Nanostoma, one of which seems to be 
identical with Pacilichthys zonalis Cope. These species cannot well be 
referred to Pecilichthys, as they have a complete lateral line. From 
