VI'2 



first, Stilbe,'' one and two fifths to one and three fourths the length : 

 Ohrosomns, Hyborhynchus and Piraephales, two and two fifths to 

 two and two thirds ; and Hybogonathas, four times. The intestines 

 in these are generally filled with a soft, dark-colored slime, without 

 remains of insects, but of vegetable origin. In the remarkable genus 

 -Campostoma, the canal eiitend^ to between eight and nine times 

 the length, and, like that of other vegetable feeders, is usually found 

 occupied by the ingesta for a considerable part of its length." 



This statement is in the main correct, as far as it goes, but it 

 will be seen from the following data, and from the discussion of 

 the food of the family, that it is far from the truth with respect to 

 the genus Carapowtoma and its allies. 



If we examine the alimentary structures of the Cyprinida'. to which 

 reference has been made in describing the food of the preceding 

 families, we shall find these fishes easily divided into at least four 

 tolerably distinct groups, defined by characters drawn from the gill- 

 rakers, the pharyngeal teeth, and the intestines. In all but two of 

 the genera of this paper* the gill-rakers are short and insignificant. 

 The pharyngeal teeth may be either hooked or plain, and with or 

 without grinding surface, while the intestine varies in length from 

 less than that of the body without the head to seven or eight times 

 the length of the head and body together. For convenience sake, 

 I have grouped the genera as follows : — 



Group I. — Intestine long. Pharyngeal teeth not or slightly hooked, 

 with grinding surlace. 



Catnpostoma, Plmepliales, Hi/horliyncltiis, Hi/hognathaa. 



Group II. — Intestine rather long. Teeth hooked, with grinding sur- 

 face. 



XotemU/ou us, Chrosomus. 

 Group III. — Intestine short. Teeth hooked, with grinding surface. 



Hi/hopsis, Luxilus, Lythriiriis, Hemitrc.mia, Puttyf/ohio. 



Group IV. — Intestine short. Teeth hooked, without grinding sur- 

 face. 

 Mtiiiitliis, Pliofoncnis, Er'u-ijiuhn, Plu'iuicoh'tiis, Scmotlliis, Cern- 

 tichthys, lili in ichthys. 



The second group, consisting of Notemigonus and Chrosomus, may 

 be again divided according to the development of the gill-rakers, 

 which are numerous, long and slender in Notemigonus ; few, short 

 and insignificant in Chrosomus. 



FOOD OF THE YOUNG. 



The geneva and species of Cyprinidfe are not easily recognized, 

 even in the adult, ♦the characters upon which they are based being 

 often either trivial or extremely variable; and when oue has to do 

 ■with individuals small enough to show the earliest food of the fam- 

 ily, it is commonly quite impossible to identify even the genus. In 



■'Notemigonus. 



*I have us(m1 hero. for ('onv»>nion<'(> sako. tlu- iioinru.'lntiiro <«f tln> ('at;ilo}ini> of the Pisho^ 

 -of lUinois, puhlished in our third bulletin. 



