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462 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
front of the eye. Eye small, anteriorly placed, its diameter 13 in snout, 
7 times in the length of the head. Isthmus very narrow, the gill-open- 
ings extending forward below. Teeth 2,5-4, 2; one of the teeth in the 
larger series with a broad, flattish, grinding surface, the others convex ; 
the teeth comparatively short and stout. Seales large for the genus, 
‘subequal over the body, rather smaller on the belly, their texture firm, 
their exposed surfaces very broad and hexagonal. Dorsal fin inserted 
directly over the ventrals, behind the middle of the body. Caudal fin 
evenly forked, on a stout, rather long caudal peduncle, the rudimentary 
rays at its base not more than usually developed. Pectorals not long, 
extending three-fifths the distance to the ventrals; the ventrals about to 
the vent; the lower fins all short. Fin-rays: Dorsal 9; anal 8. Scales 
10-55-5. Length of head contained 34 times in the total length to the 
base of caudal; the greatest depth of the body about the same. 
Color blackish, fins all dusky. The ground shade is somewhat sil- 
very, but the color is rendered very dark by the large number of small 
black specks. 
The typical specimens, two in number, are about a foot in length. 
This is therefore one of the largest members of the genus. 
10. Apocope vulnerata Cope. 
Numerous specimens, some of them 5 inches in length. The large 
specimens have the lateral line developed anteriorly only. Pectoral fins 
short, not reaching nearly to ventrals. Lat. 1. about 70. 
11. Chasmistes liorus Jordan.—June Sucker. 
A considerable number of fine specimens of this interesting species 
are in the collection, all of them about 18 inches in length. Color oliva- 
ceous above, with dusky mottlings formed of dark points; belly white; 
fins chiefly pale, shaded at the tips with dusky. Anal and lower lobe 
of caudal tuberculate in the males. Body slender, heavy at the shoul- 
ders, somewhat compressed, the caudal peduncle stoutish; depth of body 
at the shoulders half more than its thickness. Head not conic, low at 
the nape, and strongly concave in profile above, from the great promi- 
nence of the premaxillary spines, which form a conspicuous nose, elevated 
above the eye, and with its top even with the interorbital space, which 
is very broad and nearly flat. Preorbital large; suborbital moderate. 
Mouth large and very oblique, anteriorly on the level of the suborbital 
bones; the mandible strong, placed at an angle of 45°, its base below 
the nostrils, its lengta equal to that of the snout, which is about three- 
sevenths that of the head. Upper lip somewhat protractile, narrow, 
vertical, its edge smooth; lower lip narrow, the two lobes well sepa- 
rated, very faintly plicate, the plice slightly uneven. No cartilaginous 
sheath to the jaws. Interorbital space nearly equal to length of snout. 
Eye small, exactly median, 7 in head. Isthmus as broad as eye. Phar- 
yngeal teeth essentially as in Catostomus. Scales much reduced in size 
and crowded anteriorly, those on the breast imbedded in the skin. Scales 
