BULLETIN OF TIIE UNITED STATES FISII COMMISSION. 59 



three-eighths of the distance from the snout to the base of the caudal, 

 the soft dorsal two-thirds of this distance, and the anal immediately un- 

 der the first ray of the soft dorsal. The single spine of the anal is soft 

 and weak. 



The pectorals and the ventrals extend backward to about the same 

 point, a little more than half-way from the base of the pectorals to the 

 commencement of the anal. The caudal peduncle forms about one- 

 fourth of the length exclusive of the caudal fin. 



In color this fish, while living, resembles the other species of this 

 genus, being indeed almost as pellucid as A. beanii ; and at first it was 

 supposed to be that species. The sides are ornamented with about 10 

 dusky blotches, most distinct posteriorly. Along the back there are 

 about 14 similar blotches. The occiput is sprinkled with black specks, 

 and a few of these are scattered over the snout. The belly, chest, and 

 lower parts of the head are colorless. The fins appear to be marked in 

 no way except with a few black dots. 



Only a single specimen of this species was secured. Its length to the 

 base of the caudal is 1§ inches, taken from the Pearl River at Jackson, 

 Miss. 



2. Ammocrypta beanii Jor. — Bean's Darter. 



Ammocrypta gelida, Hay, Proc. U. S. Nat. Museum, in, 1880, 490. 



One specimen of this species was taken, along with the preceding, from 

 the Pearl Eiver at Jackson. It is but an inch and one-eighth long, and 

 resembles those taken in Eastern Mississippi, and described, as cited 

 above, under the name of A. gelida. I have no doubt now, however, that 

 they ought to have been included under Professor Jordan's species. 



3. loa vigil, sp. nov. 



The following description is drawn from a single specimen, which has 

 a length of 1 inch to the base of the caudal : 



Body slender, head long, caudal peduncle compressed and compara- 

 tively deep. The fish, therefore, appears to have nearly the same depth 

 everywhere. 



Top of the head sloping gradually from the occiput to the snout. 

 Length of the head in that of the body, 3f times ; therefore long and 

 pointed. Upper jaw projectile, the furrow separating the skin of the 

 premaxillaries from that of the forehead being evident. Mouth large, 

 terminal, slightly oblique j the jaws equal. The maxillaries extend back 

 to a vertical from the anterior edge of the pupil. The jaws both straight, 

 the tip of the lower not being curved downward, as in A. pellucida. Up- 

 per and lower jaws armed with recurved teeth. Vomer apparently with 

 teeth. 



Opercular spine well developed. Opercles and cheeks apparently 

 devoid of scales. Eye large, its diameter in the length of the head 3 

 times, exceeding the length of the snout. Interorbital space very nar 

 row. 



