ART.i TREMATODE PARASITES OF BIRDS LINTON 11 



Lams delaacarensis. 



1914, January 24. 11. These distomes are rather more slender 



than are those from the other species of gulL 

 In a series of sections the cirrus appears to 

 be smooth. The ova are large, 0.11 by 0.06 

 in a whole mount, and from 0.08 by 0.04 to 

 0.12 by 0.05 in sections. (Cat. No. 7922, 

 U.S.N.M.) 



Loffus tnarinHS. 



1922, January 10. 1. (Cat. No. 7923, U.S.N.M.) 



Latnis 'Philadelphia. 



1913, April 13. 1, fragment, posterior end missing. 

 Nycticorax nicticoraw tiaevitts. 



1914, September 11. 1. (Cat. No. 7924, U.S.N.M.) 



HnULASTHLA INCISA, new species 

 Figures 21-33 



From intestine of white-winged scoter {Oideima deglaiidi). 



Head reniform and surrounded by a circle of about 27 spines unin- 

 terrupted dorsally ; neck short, concave beneath, densel}^ covered with 

 minute spines set in transverse rows. Margins of neck finelj^ serrate, 

 the serrations becoming more marked posteriorly, the body from a 

 level a little back of the ventral sucker to near the posterior end 

 being transversely and sharply corrugated. Body nearly linear, and 

 rather slender. Oral sucker nearly circular; pharynx longer than 

 broad, near oral sucker; ventral sucker circular and much larger 

 than oral. In sections there appeared to be a short esophagus, 

 although none could be seen in the whole mount. The intestinal 

 rami extend to the posterior end of the body. The genital pore opens 

 immediately in front of the ventral sucker ; cirrus-pouch and seminal 

 vesicle extend far back of the ventral sucker ; in the mounted speci- 

 men the posterior end of the seminal vesicle was 1.25 mm. back of the 

 ventral sucker. The testes are oval-elliptical, one following the 

 other, and near the posterior end of the body. The subglobular 

 ovary is situated a little to the right of the median line in front of 

 the first testis, from which it is separated by the relatively large 

 shell-gland, vitelline reservoir, and beginning of the uterus. The 

 vitellaria are abundant and extend from the posterior end of the 

 body to within a short distance (0.5 mm. in the mounted specimen) 

 of the ventral sucker. The uterus fills the central space between the 

 vitellaria from the ovary nearly to the seminal vesicle, from which 

 point the metraterm leads to the genital pore; ova rather numerous, 

 about 0.112 by 0.057 in the two principal diameters. Some details 



