736 



GEOLOGICAL SURVEY OF THE TEEEITOEIES. 



Male. — (Fig. 63, . rt, magnified ten times.) Body cylindrical, ratlier 

 short and thick; head c^iindrical, pointed, conical, much slenderer than 



Fig. 63a. 



Fig. 63b, 



Fig. 64. 



EUSTRORGYLUS BUTEONIS. 



EUSTRONGYLUS BUTEONIS. 



EUSTRONGYLUS CHORDEILIS. 



the other end. I can perceive no papillae arouDd the end of the head. 

 Eud of the body rather more incurved than in the female, bluntly 

 conical ; penis forming a single spiculum, a little curved, and inclosed in 

 a bivalved sheath, one valve being truncate and the other pointed, and 

 reaching nearer the end of the penis than the truncate valve. 



Length .40 inch. Tvio individuals. 



Female. — (Fig. 63, h, magnified ten times.) Over twice as large as 

 the male ; the body short and thick ; the head subacutely conical, with no 

 papillfB that I can see; end of the body obtuse; extreme tip slightly 

 mucronate. 



Length one inch. Two individuals. 



Four spet.'imens, taken from " under the eyes of Buteo Swainsoni, (IsTo. 

 269,) collected September 15, 1872, at Snake Eiver, Wyoming Territory," 

 by C. H. Merriam. 



Uustrongylus chordeiUs, n. sp. (Fig. 64, magnified ten times.) 



An outline figure of a worm, generically identical with IJ. httteonis, is 

 introduced in order to bring out more clearly the specific characters of 

 the latter species. Two females were taken by Mr. 0. A. Walker "from 

 the brain of the night-hawk, {ChordeiUs Virginianus,) shot in June, at 

 Oampton, New Hampshire, and presented to the museum of the Peabody 

 Academy of Science, at Salem, Massachusetts. It is a much slenderer 

 form than U. buteonis, but much shorter and thicker than the species 

 described and figured by Professor Wyman. Both ends of the body are 

 much alike, the anal end being much more pointed than in JE. hutconis, 

 and the anterior end of the body less tapering. 

 Leuath .70 inch. 



