826 FISHES—CATOSTOMIDZ. 
opercular bones moderately developed, nearly smooth; isthmus broad; gill-rakers 
feeble; pharyngeal bones rather weak, the teeth moderate, strongly compressd, the 
lower five or six much stronger than the others which diminish rapidly in size upward, 
each with a prominent internal cusp; scales large, quadrate, nearly equal over the body 
and not crowded anteriorly, usually about 44 in the lateral line, and about 12 series 
between dorsal and ventrals; lateral line well developed, straight or anteriorly curved ; 
fins well developed, the dorsal inserted about midway of the bsdy, its first rays usually 
nearer snout than caudal, the number of rays usually 13 (11 to 17); anal fin short and 
high, emarginate in old males, with seven rays; ventrals inserted under middle of dor- 
sal, usually with nine rays; caudal fin deeply forked; air-bladder with three chambers ; 
skeleton essentially as in Catostomus, the vertebrae (in M. carpio) 27-14; sexual pecu- 
liarities little marked, the males in the spawing season (March to June) with the lower 
fins reddened, and the anal rays swollen and tuberculate. 
Species numerous and very closely related, abounding in all waters of the United 
States, east of the Rocky Mountains. 
ANALYSIS OF SPECIES OF MYXOSTOMA. ’ 
“Lower lip infolded, A-shaped when viewed from below, with a distinct median 
crease, in which the two halves of the lip meet forming an acute angle; mouth 
small; dorsal rays 16. 6 6 5 5 : : : VELATUM. 43. 
**Lower lip full, its posterior edge truncate, not infolded or A-shaped. 
a. Dorsal rays 12 to 14. 
b. Caudal fin with the upper lobe falcate, much longer than the lower. 
ANISURA. 44, 
bb. Caudal fin symmetrical. 
c. Mouth very small; head short,5 to5}inlength. . . . AUREOLUM. 45. 
cc. Mouth rather large; head larger, 4 to 5 in length. 
MACROLEPIDOTUM. 46. 
aa. Dorsal rays 15 to 18; mouth large. 5 5 ° : 6 CARPIO. 47. 
43. MyxostoMaA VELATUM (Cope) Jordan. 
Small-mouth Red Horse; White Nose. 
, Catostomus anisurus, KIRTLAND, Boston Journ. Nat. Hist.,-v, 1845, 269 (with plate). (Not 
of Rafinesque. )—STORER, Synopsis, 1846, 424. 
Ptychostomus anisurus, JORDAN, Bul. Buffalo Soc. Nat. Hist., 1876, 94 (name only). 
Moxostoma anisurus, JORDAN, Man. Vert., 1876, 295. 
Teretulus anisurus, NELSON, Bull. No. 1, Ills. Mus. Nat. Hist., 1676, 49.—JORDAN and 
COPELAND, Check List, 1876, 153 (name only). 
Moxostoma anisurum, JORDAN, Proc. Acad. Nat. Sci. Phila., 1877, 72, 80. 
Moxostoma anisura, JORDAN and GILBERT, in Klippart’s Rept., 1877, 53 (name only). 
Myxostoma anisura, JORDAN, Bull. U. S. Nat. Mus., x, 1877, 33. 
Ptychostomus velatus, CopE, Proc. Am. Philos. Soc., 1870, 471. 
Moxostoma velatum, JORDAN, Man. Vert., 1876, 296. 
Teretulus velatum, NELSON, Bull. No. 1, Ills. Mus. Nat. Hist., 1876, 49. 
Teretulus velatus, JORDAN and COPELAND, Check List, 1876, 158. 
Moxostoma velata, JORDAN and GILBERT, in Klippart’s Rept., 1876, 53 (name only). 
