AUT. 13 TREMATODE PARASITES OF MARINE MAMMALS PRICE 21 



Remarks. — The foregoing description, taken from Skrjabin 

 (1915)/ was based upon specimens collected by Doctor Staroka- 

 domsky, February 8, 1912, in north Russia, near Kaluchinskaya 

 Bay. 



Family ECHINOSTOMATIDAE Loess, 1902 



Family diagnosis. — Body more or less elongate, small or very 

 large, usually much flattened anteriorly, less so, or even cylindrical, 

 posteriorly. Oral sucker small and weak, surrounded dorsally and 

 laterally, but not ventrally, by a collarlike fold, bearing one or two 

 rows of spines, which are continued laterally to ventral corners, 

 the corner spines usually large or specialized ; acetabulum large and 

 powerful, usually preequatorial and near oral sucker. Cuticle usu- 

 ally spinose, especially anteriorly. Excretory vesicle Y shaped, with 

 lateral twiglike branches. Pharynx and epithelial " pseudoesoph- 

 agus " present ; intestinal ceca extend to posterior end of body. 

 Genital aperture preacetabular; genital sinus present or absent; 

 cirrus pouch usually present. Testes postequatorial, usually tandem 

 in position. Ovary pretesticular, usually to right of median line; 

 Laurer's canal present. Vitellaria lateral, rarely extending anterior 

 to acetabulum. Uterus in transverse coils, rarely extending beyond 

 intercecal field. Parasites of intestines or bile ducts of vertebrates, 

 especially birds. 



Type genus. — Echinostoma Rudolphi, 1809. 



Genus ECHINOSTOMA Rudolphi, 1809 (sensu lato) 



Generic diagnosis. — Characters of the family. 



ECHINOSTOMA ACANTHOIDES (Rudolphi, 1819) Cobbold, 1860 



SynonyTn. — Distoma acanthoides^ Rudolphi, 1819, p. 114. 



Description. — Ecldnostoma: Body elongated and flattened (4 mm 

 to 6 mm long, according to Dujardin, 1845), divided into a somewhat 

 slender (271/x wide) anterior part and a broader (520/* wide) poste- 

 rior part (Dujardin gives the maximum width of the body as 750/1.) 

 the two portions being united at the level of the acetabulum. Oral 

 sucker 15G/x long by 135/i wide; acetabulum 375/t long by 396/a wide, 

 situated about one-third of the body length from the anterior end. 

 Cephalic collar provided with four spines, 73ju, long, on each ventral 

 lobe, with 16 to 18 smaller spines, 59/i long, arranged around the mar- 

 gin in a single row, uninterrupted dorsally, and with one small spine, 



^ The writer Is indebted to Dr. R. Ed. Schulz, of the School of Veterinary Medicine, 

 Moscow, for a tjpt'writton cojiy of Professor Skrjabin's paper, the publication in which 

 this paper appeared being unavailable in this country. 



