1-1 PROCEEDINGS OF THE ACADEMY OF [1885. 



A REVIEW OF THE SPECIES OF THE GENUS SEM0TILTJ8. 

 BY ERNEST P. BICK.NELL AND FLETCHER B. DRESSLAR. 



In this paper we give the synonymy of the species of the genus 

 Semotilus, with an analytical key by which they may be distin- 

 guished. 



The specimens which we have studied belong to the Museum 

 of the Indiana Universit}', most of them having been collected 

 by Professor David S. Jordan. 



SEMOTILUS. 



Semotilus Rafinesque, Ichtta. Ohiensis, 1820, 49 (dorealia.) 

 Leucosomus Heckel, " Russegger's Reise, 1841, 1042 " (argenleus.) 

 Cheilonemus Baird, Storer's History Fishes Mass., 1856,285 (pulchellus.) 



Analysis of Species of Semotilus. 



a. Origin of dorsal fin about midway between middle of orbit and 

 base of caudal ; body rather robust, especially anteriorly. 

 Vertebne ' 22 + 20 ; the interneural spine of first dorsal ray 

 inserted between fifteenth and sixteenth neural spines. A 

 distinct black spot on anterior part of base of dorsal ; color- 

 ation dusky, little silvery, rosy below in spring. 

 h. Scales comparatively small, crowded anteriorly, their number 

 about 10-54-1 ; head large and broad, its length 3^ in 

 head ; maxillary barbel very small, indistinct in young 

 specimens; eye small, 6 to 7 times in head (in adult); 

 dusky bluish above, paler below ; belly white ; size medium, 

 reaches a length of about a foot. atromaculatus. 1. 



66. Scales rather large, not crowded anteriorly, their number 

 about 9-48-5 ; head 3| in length ; maxillary barbel well 

 developed ; eye rather large, its diameter about four in 

 head in young ; dark bluish above and on upper part of 

 Bides, becoming rather abruptly light below lateral line; 

 Bize small, attains a length of 3 inches or more. 



tho?-eauianus. 2. 



1 In Semotilus atromaculatus. This character has not been verified in S. 

 auianvi. 



