98 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY III 



Early writers on fishes, as weiJ hs raost foreign ichtbyologists, have 

 considered the Buckers as forming a mere tribe or subfamily of the 

 Gyprinidce, which gioui) has been variously denominated Catostomi, 

 Catostomina, and Catcetominw, but the characteis above noted, of teeth 

 and luoutli, seem to the writer to fully justify their separation as a dis- 

 tinct famih Tie dorsal fin in Cafostomidcc is more developed than is 

 usual in American CjpHnidce, although various Old World genera show 

 similar characters. The development of the lips and the great protmc- 

 tility of the mouth are I'eatuies usually diagnostic, but in the genus 

 Quassi'abia the mouth is scarcely i^rotractile, and among our Gypri- 

 nidce certain species of Phenacobivs and Ceratichthys have thicker lips 

 than have some of the Catostomidce. 



The Catostomidce fall at once into three well-marked subfamilies, first 

 indicated by Professor Gill, and termed by him Catostomince^ Cycleptince, 

 and Buhalichthijincc. These may be characterif.ed as follows: — 



Caiostomince. — Body oblong or elongate, subterete or more or less 

 compressed : dorsal fin nearly median, short and subquadrate, with 

 from nine to eighteen developed ravs: ventral fins under the dorsal, of 

 nine or ten rays : anal fin high and short, normally of seven rays, nearer 

 the base of the caudal tb;in that of the ventral fi?!S : lips well developed, 

 usuallj' papillose or plicate : gill-rakers little developed. Genera Quassi- 

 lahia. PIacophary7ix, Myxostotnci, Erimyzon, Minytrema, Chasmistes, 

 Catostomus, Pantosteus. 



Cycleptincc. — Body elongate, slender: dorsal fin falciform, of about 30 

 rays, beginning over the interval between the pectoral and ventral fins, 

 and extending as far back as the beginning of the anal fin : ventral fins 

 10 rayed; anal fin small, of about 7 rays: head extr'^mely small: scales 

 moderate, with the exposed surfaces broad : fontauelle entirely obliter- 



times absent ; the head is diversiform; the opercular bones normally developed ; the 

 nostrils double ; the mouth more or less inferior, and provided with fleshy and gener- 

 ally papillose or crenated lips ; the upper jaw is formed on the middle by the small 

 and lamelliform interniaxillaries, and on the sides by the supramaxillaries ; teeth are 

 wanting in thejav?-;; the pharyngeal bones are developed in a falciform manner, and 

 provided with a row of numerous comb-like teeth ; the branchial apertures are re- 

 stricted to the sides; brauchiostegal rays three on each side ; dorsal variable in devel- 

 opment; anal posterior, and generally short and high; caudal large, and more or less 

 emarginated; pectoral fins low down, but lateral and with their rays branched; ven- 

 tral fius abdominal ; the intestinal canal is very long ; the stomach simple and desti- 

 tute of pyloric caeca ; the air-bladder is large, unprotected by an osseous capsule, and 

 •divided by transverse constrictions into two or three regions." 



