ART. 18 THE TREMATODE FAMILY SCHISTOSOMIDAE PRICE 31 



specimens, the width being 450)ii to 650/a and the thickness about three- 

 fourths of the width. Anterior end of body either pointed or bhint, 

 depending upon the amount of contraction during fixation ; posterior 

 end provided with peculiar lobelike projections which give it the 

 appearance of being obliquely truncate. Suckers absent. The gynae- 

 cophoric canal is reduced to a groove-like depression, 550/i to 750/x 

 long by lOOfx wide in flattened specimens, and situated 500/a from 

 anterior end of body. Oral opening terminal; esophagus 180/i. long; 

 intestinal ceca short and united posteriorly at anterior end of gynae- 

 cophoric canal ; common cecum long and terminating near posterior 

 end of body. Testes consist of numerous follicles situated along 

 the course of the common cecum. Terminal portion of genital system 

 (Endapparat) consists of a cirrus pouch containing the ejaculatory 

 duct, prostate, and a portion of the seminal vesicle, and is situated 

 between the branches of the intestinal ceca. The genital pore is 

 situated on a small papilla at the anterior end of the gynaecophoric 

 canal and slightly to the left of the median line. 



Femole 30 to 35 mm. long, slender, circular on cross section, and 

 lOO/u, to 120)ii in diameter. Anterior end of body attenuated ; the pos- 

 terior end is similar to that of the male. Esophagus TOOju, to 900/i, 

 long; intestinal ceca unite posteriorly about 2 to 3 mm. from anterior 

 end of body; common cecum slender and extending to posterior ex- 

 tremity of body. Ovary tubelike and spiral, situated anterior to the 

 cecal union. The oviduct arises from the posterior pole of the ovary 

 and passes to a large seminal receptacle, and then extends forward 

 ventrally to the ovary and unites with the vitelline duct a short dis- 

 tance in front of the ovary. Vitellaria unpaired, composed of 

 rounded follicles extending from the cecal union to the posterior end 

 of body. Uterus short and containing but one o^g^. Genital pore 

 median, about 60/x from the anterior extremity. Egg oval, about 

 lOOja long. 



Cercaria unknown or unrecognized. 



Hosts. — Primary, birds {Larus fuseus, Hydrocoloeus melano- 

 cephalus and FI. ridihundus) ; secondary, unknown. 



Location. — Intestinal veins. 



Distribution. — Europe (Sweden and England). 



BIBLIOGRAPHY 



AsCAlSriO-RODRIGUEZ, J. B. 



1916. Revision de nuestras (?) distomatosis hepaticas. Vargas, Caracas, 

 vol. 7, February 20, pp. 83-92. 

 Baktsch, Paul. 



1925. Some new intermediate hosts of the Asiatic human blood fluke. 

 Journ. Wash. Acad. Sci., Bait., vol. 15, February 19, pp. 71-73. 



