1913. 



NATURAL SCIENCES OF PHILADELPHIA. 



67 



Fig. 1. — Rutilus olivaceus (Cope). (Type of Leucns olivaceus Cope.) 



Nos. 19,392 (type) to 19,399, A. N. S. P., cotypes of Leucus 

 dimidiatus Cope. 



Nos. 19,882 (type) and Nos. 18,654 to 18,691, A. N. S. P., co- 

 types of Siphateles vittatus Cope. 



The young differ from the adults in the projecting mandible, 

 large eye, more or less incomplete 1. 1., and nearly straight convex 

 upper head profile. The predorsal scales appear to become more 

 numerous with age. 



Rutilus oregonensis Snyder- is said to differ in'^the teeth, which 



Fig- 2. — Rutilus olivaceus (Cope). (Type of Leucus dimidiatus Cope.) 



2 Bull Bur. Fisher., XXVII, 1908, p. 87. 



