462 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



front of the eye. Eye small, anteriorly placed, its diameter If in snont, 

 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. Scales large for the genus, 

 subequal over tlie body, rather smaller on the belly, their texture firm, 

 tlieir exposed surfaces very broad and hexagonal. Dorsal fin inserted 

 directly over the ventrals, behind the middle of the body. Caudal tin 

 evenly forked, on a stout, rather long caudal peduncle, the rudimentary 

 rays at its base not more than usually develoi^ed. 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 3J 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 develoijed 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 oliAa- 

 ceous above, with dusky mottlings formed of dark points; belly white; 

 tins 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 i^eduncle 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, i)laced at an angle of 45°, its base below 

 the nostrils, its length 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 plicae slightly uneven. No cartilaginous 

 sheath to the jaws. Interorbital space nearly equal to length of snout. 

 Eye small, exactly medinn, 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 



