FISHES OF NEW YORK 637 



end of Cayuga lake. It is extremely variable in size, color and 

 length of fins and number of rays. 



This species grows to a length of 7 inches under favorable 

 circumstances and is one of the most destructive enemies of the 

 eggs and young of brook trout and other members of the salmon 



family. 



Genus URANIDEA De Kay 



This genus is very close to C o 1 1 u s , from which it differs in 

 the reduction of its ventrals to a concealed spine and three soft 

 rays, a step further in the degeneration characteristic of fresh- 

 water types. The skin is smooth, or very nearly so, the pre- 

 opercular spines small, and there is usually no trace of teeth on 

 the palatines. Cold streams and springs of the United States 

 from New England and the Great lakes to the Pacific coast. 



310 Uranidea gracilis (Heckel) 

 Miller's Thumb 



Cottus gracilis HECKEL, Ann. Wien Mus. II, 148, 1837, New York; GIRARD, 



Monograph Fresh-Water Cottoids N. A. 49, pi. 1, figs. 11, 12, 1851; 



GUNTHER, Cat. Fish. Brit. Mus. II, 157, 1860; MEEK, Ann. N. Y. Ac. 



Sci. IV, 315, 1888; E.UGENE SMITH, Proc. Linn. Soc. N. Y. 1897, 40, 1898. 

 r ran idea quiescens DE KAY, N. Y. Fauna, Fishes, 01, pi: 5, fig. 14, 1842, 



stream and lake in Hamilton county, N. Y. 

 U ran idea gracilis JORDAN & GILBERT, Bull. 10, U. S. Nat. Mus. 099, 1883; 



BEAN, Fishes Penna. 137, 1893; JORDAN & EVERMANN, Bull. 47, U. S. 



Nat. Mus. 1908, 1898. 



The body is moderately slender, spindle-shaped; mouth large, 

 the upper jaw reaching nearly to the middle of the eye. The 

 preopercular spine is moderately large, covered by skin. The 

 pectorals reach to the origin of the anal, and the ventrals to the 

 vent. The depth of the body is one fifth, and the length of the 

 head two sevenths of the total without caudal. Teeth in villi- 

 form bands on the jaws and vomer, none on the palatine bones. 



D. VIII, 16; A. 12. 



The sides are olivaceous, mottled with darker; a red margin 

 on spinous dorsal. 



The miller's thumb or little stargazer is an inhabitant of New 

 England and New York. In Pennsylvania it occurs in the head- 



