ART. 13 TREMATODE PARASITES OF MARINE MAMMALS PRICE 53 



and muscular, both circular and longitudinal fibers being present. 

 The seminal vesicle is slender and greatly convoluted, and occupies 

 the basal third of the cirrus pouch. A definite pars prostatica 

 appears to be absent although some prostate cells are present along 

 the distal, less convoluted portion of the seminal vesicle. The cirrus 

 is slender, about 2 mm long, unarmed and protrusible. The genital 

 aperture is ventral and situated at the posterior end of the body 

 at the junction of the muscular rim with the body proper. The 

 testes are deeply lobed, about 850^ by 620(0,, extracecal and opposite 

 each other in the posterior third of the bod3^ The ovary is irregular 

 in outline but not deeply lobed, about 435/x in diameter, situated 

 to the right of the median line, intercecal and pretesticular. Mehlis's 

 gland is composed of large piriform cells and is situated median 

 and slightly dorsal to the ovary. The seminal receptacle is mus- 

 cular, more or less oblong, about 697fi long by 155/x wide, and situated 

 dorsal to Mehlis's gland. There is no Laurer's canal. The vitel- 

 laria consist of relatively few, large, irregularly shaped follicles 

 situated in the intercecal space between the equator of the body 

 and the testes ; the follicles are not divided into two separate groups 

 as in 0. dujonis^ but form a single, more or less grapelike mass. The 

 uterus is greatly convoluted, forming a wreathlike mass of loops 

 which occupies the greater part of the central portion of the body; 

 the loops extend slightly beyond the ceca laterally, but do not extend 

 anteriorly beyond the intestinal bifurcation. The terminal portion 

 of the uterus is continued as a muscular walled, slightly sinuous 

 vagina or metraterm, which runs dorsal to the cirrus pouch and opens 

 beside the male genital aperture. The eggs are oval in shape, 18/i 

 long by 11/A wide, light straw colored, and provided with a long, 

 slender filament at each pole. 



Hosts. — Trichechus manatus and T. latirostrls {^Mavafus Jati- 

 rostris.) 



Location. — Nasal passages and stomach. 



Distrihution. — North America (United States — Philadelphia, Pa,), 

 and Tropical America. 



SpeeimeTis.—V.S.'^M. Helm. Coll. No. 1732. 



Remarks. — In a note presented at a meeting of the Philadelphia 

 Academy of Natural Sciences, Leidy (1891) reported the occurrence 

 of Amphistonium fabacev/m Diesing in a sea cow, Manatus latirostris, 

 which died in the zoological garden. These specimens had been col- 

 lected from the large intestine and submitted by Dr. H. C. Chapman. 

 In the same note he said : " Numerous specimens, many of larger 

 size, up to 11 mm long by 9 mm broad, were obtained from the 

 nasal passages of another sea cow, and were presented to the 

 Academy by Jacob Geismar." 



