I PROCEEDINGS OF THE NATIONAL MUSEUM VOL.73 



Parasite Host 



Ascocotyle plana, new species Butorides virescens. 



Levinseniella adtinca (Linton) Crocethia alba. 



Parorchis avitus Linton Lams argentatus. 



Oalactosomum cochleariforme (Rudolphi) Fregata maffitificetis. 



Minuthorchis sanguineus, new genus and species Larus atricilla. 



Distomum sp. A Oidemia perspicillata. 



Distomum sp. B Oidemia perspicillata. 



OrnitJiohilharzia sp Larus argentatus. 



Philadelphia. 

 Nycticoraw nycticorax naevius. 

 Oidemiii deglandi. 

 Proalaria indistincta (Guberlet) Larus argentatus. 



atricilla. 



Alaria sp Larus delawarensis. 



Strigea bursigera (Brandes) Larus argentatus. 



atricilla. 



delawarensis. 



HAEMATOTREPHUS FODIENS. new species 

 Figures 1-6 



Free in intestine and encysted in pancreas of a loon {Gavia im/mer) . 



Body of free worm nearly linear, narrowing slightly toward the 

 anterior end; anterior half finely rugose; mouth small, terminal: 

 anterior tip of body a subtriangular, muscular disk — the oral sucker ; 

 no ventral sucker certainly made out. Pharynx near mouth, pyri- 

 f orm ; esophagus about twice the length of pharynx ; intestinal rami 

 extend to posterior end, where they appear to unite. Testes two, 

 roundish, diagonally placed near the posterior end, and separated 

 from each other by a space equaling or exceeding the diameter of a 

 testis ; seminal vesicle on the left side of the genital pore, which is on 

 the median line at about the anterior sixth of the body. Ovary 

 somewhat lobed, in front of the anterior testis and nearly on the 

 median line. The seminal receptacle lies on the right posterior border 

 of the ovary, and on the left anterior border of the first testis. The 

 shell-gland lies along the anterior side and to the right, of the ovary. 

 The uterus is very voluminous and fills the greater part of the 

 interior of the body as far forward as the genital pore. Ova small 

 and very numerous. The vitellaria lie between the lateral margins 

 of the body and the intestinal rami, and extend from about the 

 anterior fifth to near the posterior end. 



Dimensions of free specimen in balsam : Length 11 mm. ; breadth, 

 at genital pore 1.40, at middle 1.85, at second testis 1.68, length of 

 triangular head 0.21, breadth at base 0.35; pharynx, length 0.24, 

 breadth 0.15; length of esophagus 0.45; ovary, length 0.22, breadth 

 O.TO ; first testis, length 0.35, breadth 0.56 ; second testis, length 0.40, 

 breadth 0.52; ova 0.024 by 0.012. 



