30 CATCSTOMIDJi: CATOSTOMUS. 
125 
marked; tliefiiis liiglier in the male and the anal somewhat swollen and 
tnbercnlate in tbe spring. Breeding males in some species with a rosy 
or orange lateral band. Air-bladder with two chambers. Vertebrm in 
C. commersoni and C. nigricans 45-47. Species A^ery niimeroiiSj all be- 
longing to the United States, except the Siberian G, rostratiis Tilesiiis. 
(zarty, inferior; (7TO'j.a, month.) 
* Scales very small, much reduced and crov'ded anteriorly, 83-115 in the lateral line. 
(Catostomiis. ) 
a. Fontanelle almost obliterated, reduced to a narrow slit; each jjiwwith a well- 
developed cartilaginons sheath (as in Pantosteus). 
129. C. discolboStiis Cope. 
Body snbterete, compressed behind, the depth 5 in length. luterorb- 
ital space 2 in head. Head quite short, broad and rounded above, 4i|in 
length. Eye small, far back and liigh np, G in head. Month Awy 
large, inferior, beneath the projecting snont. Upper lip A^ery full, iien- 
dent, Avitli about 5 roAvs of tubercles. LoAver lip A^eiy full, moderately 
incised, with about 10 rows, a notch separating tlie upper lip from the 
lower. Each jatv with a slightly curved cartilaginons sheath on its 
edge, the tAVO parallel Avith each other and fitting closely together. 
Fins small. Dorsal 11; caudal little forked; scales 15-90-11, irregular. 
Colors dusky. Size small. Idaho to Wyoming and Arizona. 
(Cope, Hayden’s Geol. Surv. AAyom. Terr. 1870,435; Joi'dan, 1. c. 179. ) 
aa. Fontanelle well developed : jaws without evident cartilaginous sheath. 
0 . Upper lip very broad, with several (5 or (i) rows of large papillue. 
130. €. latipisasios Baird & Girard. 
Body slender and elongate ; the caudal pediinele especially long and 
very slender; the depth 5 ^ in the length. Head moderate, 4^ in length, 
rather slender, Avith prominent snont and rather contracted, inferior 
month. Outline of the mouth triangular, the apex forwards. The lips 
ATry thick, greatly dcA'eloped ; lower lii) incised to the base; its pos- 
terior margin extending backAvards to opposite the eye. JaAvs Ayith a 
slight cartilaginons pellicle. Eye small, high up. Preorbital bone 
broad, scarcely twice as long as deeii. Scales long and Ioav, posteriorly 
rounded, their horizontal diameter greater than the A^ertical, 17-98 to 
105-17. Fins exc(?ssively dcA^eloped, especially in the males, the free 
border of the dorsal deeply incised. Height of each of the three A’erti- 
cal fins in the males greater than the length of the head. l>orsal 13, in- 
serted nearer snout tlian base of caudal. Oandal A’ery strong, the rudi- 
mentary rays at its base unusually dexAdoped. Least depth of tail less 
