BOLEOSOMA TESSELLATED DARTERS 



297 



The eggs are emitted at intervals, and from time to time the female 

 raises a cloud of sand by a vigorous beating with the tail, perhaps for 

 the purpose of covering them. Males in breeding dress have the 

 first dorsal spines more or less swollen, and club-shaped at the tip. 



In studying our collections, wide variation was noticed with re- 

 spect to the scaly covering of the breast and cheeks, ranging from 

 complete nakedness to complete scaliness of both, and also a con- 

 siderable variation in robustness of build. While, generally speaking, 

 specimens become more scaly northward and more slender south- 

 ward, it was not possible to make out, even approximately, any line 

 or area of division, either general or local, between the two forms, or 

 to draw any definite dividing line among the variants themselves. 

 This confusion of conditions may be illustrated by the following 

 analysis of a single collection of forty-six specimens (Accessions No. 

 28180) obtained from the north fork of the Vermilion River in Ver- 

 milion county June 6, 1901. 



