30. CATOSTOMIDyE — PANTOSTEUS. 
121 
giiming in front of veutrals and ending just before anal, of about 30 rays, 
strongly- falcate in front, tlie first and second developed rays in length 
more than half the length of the base of the fin, the rays rapidly short- 
ened to about the eighth, the length of the remaining rays being nearly 
uniform andvall short. Caudal fin large, widely forked, the lobes about 
equal. Anal fin quite small, low, of 7 or 8 developed rays, scaly at base. 
Veutrals moderat e, with 10 rays. Pectorals elongate, somewhat fal 
cate. Sexual lieculiarities somewhat marked ; the males in si)ring with 
black pigment ; the head then covered with small tubercles. Air-blad- 
der with two chambers, the anterior short, the posterior elongate. One 
species known. [xu/.Xu^, round; AsTrro?, slender. “The name means 
small round mouth.” — Eajinesquc.) 
122, C. eJoBlgatsns (Le Sueur) Ag. — Blade Horse ; Gourd-seed Sudeer; Missouri 
Sudeer; Sudeerel. 
Depth 4-5 in length ; head G-8i. Eye small, G-7 in length of head. 
Longest dorsal rays a little longer than head. Pectorals rather longer 
than head. Dorsal rays 30 ; anal 7 or 8 ; scales 9-5G-7. Coloration very 
dark, the males almost black. Size large. Length of adult 1 |-2i feet. 
31ississippi Valley; rather common. A singular and interesting fish. 
(Catostomus elongaius he Snenr, Joimi. Aead. Nat. Sci. Pliila. 1817, 103: Sderogiia- 
thus elonr/atus Guuther, vii, 23; Jordan, 1. c. 189.) 
fi3.— FAWTOSTTEUS Cope. 
Hard-headed Suchers. 
(Cope, Lieut. Wheeler’s Exitl. W. lOOth Mer. v, G73, 1870 : ty^je Minomus plafgrhyndtus 
Cope.) 
Head moderate or rather small, 4-5 times in length of body, flattish 
and rather broad above, anteriorly somewhat pointed. Eye rather 
small, usually behind the middle of the head. Suborbital bones narrow, 
as in Catostomus. Bones of head rather thick, the two parietal bones 
firmly united, entirely obliteratiug the fontanelle. Mouth rather large, 
entirely inferior ; each jaw with a more or less developed cartilaginous 
sheath, separable in alcohol, essentially as in Chondrostoma, Aerochilus^ 
and related genera. Upper lip broad, papillose, with a rather broad, 
free margin and 2 or more series of tubercles. Lower lip largely devel- 
oped, with an extensive free margin deeply incised behind, but less so 
than in Catostomus. Pharyngeal bones and teeth essentially as in Catos- 
tomns. Isthmus quite broad. Body generally elongate, subterete, and 
little comi)ressed. Scales quite small, 80-105 in the course of the lat- 
eral line and 30-35 in a cross-series between dorsal and veutrals, usually 
more or less reduced in size and crowded forward, as in Catostomus. 
