20 PROCEEDINGS OF THE ISTATIONAFi MUSEUM rov.n 



1916, July 4. Many; 602 counted. 



Larus argentatus. 



1914, January 22. Many ; 1,504 counted. 



1915, January 22. Many ; 357 counted. 

 February 18. 1. 



October 5. 25. 



1916, January 6. 1. 



8. 23. 



1917, January 18. 104. Vinal Edward's note was : " Many small 



worms." 

 1927, August 13. 113, from intestines of 2 gulls. 

 Larus atricilla. 

 1911, August 15. Recorded, but number not given, adult. (Cat. 



No. 7938 U.S.N.M.) 

 Larus delawarensis. 

 1914, January 24. 2, adult with ova; length 1.33 breadth 0.46; 



ova 0.04 by 0.02. (Cat. No. 7939, U.S.N.M.) 



ASCOCOTYLE PLANA, nevr species 



Figure 50 



Two small distomes, collected from the intestine of a green heron 

 (Butorides virescens) , at Woods Hole, September 11, 1912, althougii 

 they are devoid of the circle of spines around the oral sucker, and 

 of spines on the body, which are characteristics of Looss's genus 

 Ascocotyle,^ are in such close agreement in other respects with that 

 genus that it seems best to regard the spines as an evanescent 

 character. 



Outline of body ovate, tapering to the anterior end, bluntly 

 rounded posteriorly, broadest at about the posterior third. Oral and 

 ventral suckers small, about equal, each a little broader than long; 

 pharynx nearly cylindrical, a little longer than broad; prepharynx 

 ample, somewhat saclike; esophagus slender; intestinal rami short, 

 reaching barely to the level of the anterior border of the ventral 

 sucker, which is situated at about the middle of the length of the 

 body. Genital aperture on median line at anterior edge of ventral 

 sucker; cirrus-pouch dorsal and to the left of the ventral sucker; 

 seminal vesicle large, on median line behind ventral sucker, from 

 which it is separated by a space greater than the diameter of the 

 ventral sucker. The two testes are situated at the posterior end. 

 transversely placed, their inner ends closely apposed at the median 

 line, their transverse diameter much greater than the longitudinal; 

 ovary a little to the right of the median line, between the right testis 



»Zool. Jahrb., 1899, pp. 698-9, pi. 26, fig. 2.3. 



