364 



SYNOPSIS OK THE CYI'KI NID.N OK PENNSYLVANIA. 



mens being more clumsy than the above; its length 3| in. total to origin caudal. Scales 9 — 47-9 — 6, 1)1. 7. 1* 

 17. V 8. A. 8., thirty on vertebral line in front of dorsal fin. Above blackish, scales above lateral line paler in 

 the centre; below cream-colored; checks and operclc silver orange, a dark shade through eye. Dorsal fin in old 

 males, red orange basally, except an anterior black spot. Length to end of caudal 9 in.; to base of do. 7 in. 8.5 

 I'm. ; to base of dorsal 4 in. 1 .5 lin. ; do. of ventral 4 in. 



This species has not the vigor and beauty of the last, but is perhaps more active than the 

 Ceratichthys biguttatus. It swarms in the smaller tributaries of the Susquehanna, where 

 it continually takes the bait of the fisher for more valuable prey. As an article of food 

 it is ordinary, but not to be rejected. It is less abundant in the Kiskiminitas, and 

 Youghiogheny, tributaries of the Ohio, though not at all uncommon; nor is it more plen- 

 tiful in the streams of the Delaware; outside the State, its distribution east of the Hudson 

 is not known ; it is characteristic of all the northern tributaries of the Mississippi to tin; 

 upper waters of the Platte, and is common in the tributaries of the great Lakes. A diag- 

 nosis of the allied S. pallidus, Girard, from the Platte Itiver, is introduced for comparison. 



The Semotilus corporalis is known in Pennsylvania as the "Chub." Putnam first gave 

 (in Bulletin Mus. Comp. Zool., Cambridge), its synonymy in full, which is entirely con- 

 firmed by my examinations of large series of specimens. The frontal and parietal width is 

 greater in some specimens than others, and even in the relative length of the head to the 

 body there is slight variation. In some young specimens there are no dark edges to the 

 scale sacs, and occasionally (e. g. ex. from White Iliver, la., W. P. Clark), the scales are 

 nearly as much exposed anteriorly as posteriorly. 



It is represented northeastwardly by the Semotilus argenteus (Leucosomus pulchellus, 

 Gird.) 



CERATICHTHYS, Baird, Girard. 



? Sybopsis, Girard, Pt. Proc. Acad., Phila., 1856, 210. Girard, /. c, 1856, 212. Nocomis, 

 Girard, 1. c, 190. 



This extensive genus embraces considerable variety of form and character, but forms 

 an unbroken series from one extreme to the other. Indeed it cannot be said to be; more 

 heterogeneous than our present knowledge; indicates to be the case with natural genera 

 of much extent. The three subtypes are characterized in the table below ; of these the 

 third cannot be regarded as generically distinct from the second, as the first section unites 

 in itself prominent features of the two. 



In adults of the C. cyclotis m. (the Northwestern obtuse-headed representative of the 

 C. biguttatus), the teeth are normally either 1.4 — 4.0 or 1.4 — 4.1; in half-grown speci- 

 mens (eye one-fourth head) nearly always 1.4 — 4.1; in young specimens (eye 3.5, in 

 head) always 1.4 — 4 1 ; in the last stage they resemble very much certain Ilybopses as 



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