Helminth Fauna of the Dry Tortugas. 27 



The testes are 2, subglobular, oval in flattened specimens, situated 

 a short distance behind the ventral sucker and more or less diagonally 

 placed. The ovary is in front of the left testis and close to the cirrus- 

 pouch. On its posterior border and between it and the left testis is the 

 oval or pyriform seminal receptacle. The shell-gland lies mediad of 

 the ovary and seminal receptacle. Ducts from the vitellaria meet ducts 

 from the seminal receptacle and ovary near the distal end of the cirrus- 

 pouch. The vitellaria are somewhat racemose clustered bodies, lateral, 

 and extending from the anterior border of the testis on the right side 

 and from the anterior border of the ovar}^ on the left forward to a point 

 about half-way between the two suckers. The broad neck is filled with 

 large nucleated, peripheral cells, and the inclosed parenchyma contains 

 much granular material which appears in rather ill-defined spaces. I 

 interpret these cells as j^olk-forming cells, the granular material as yolk 

 stuff, and the vitellaria as accumulated yolk (fig. 22). Beginning with 

 the shell-gland the uterus passes between the testes, its voluminous 

 folds filling the left side of the body behind the testes and returning by 

 equally voluminous folds on the right side. Again passing between the 

 testes it turns to the right and passing along the right side of the ventral 

 sucker it expands into the capacious and muscular metraterm which is 

 surrounded by glandular cells and opens with the cirrus at the genital 

 pore. The main excretory vessel was seen in sections to begin dorsal 

 to the pharynx, where it occurred in i section. In the 9 succeeding sec- 

 tions the excretory vessel appeared as a vertical slit beside the esophagus. 

 It then passed to the ventral side of the esophagus whence it continued, 

 in 6 sections, to the bifurcation of the intestine (figs. 18 and 19). In the 

 next 3 sections it passed dorsally between the intestinal rami. Thence 

 it passed on the dorsal side of the cirrus-pouch, then descending a little 

 to lie directly on the ventral sucker. It then passed ventrad to the 

 posterior end of the cirrus-pouch and seminal vesicle, between the testes, 

 then dorsal to the folds of the uterus, where for a time it was indistinct 

 because its walls were pressed close together by the distended uterus 

 Toward the posterior end it became more distinct again and was traced 

 to the terminal excretory pore which is guarded by a number of triangu- 

 lar valve-like flaps (fig. 21) The same sequence was found in two other 

 sets of transverse sections. The nature of the excretory system presents 

 the only important difference between my specimens and Looss's species. 



Host, Caretta caretta: 



1906, July I, very numerous, approximately 3,000. 



1907, June 29, 130; July 4, numerous. 



The following note is extracted from notes made at the time of 

 collecting: On July i the stomach and intestine of a loggerhead turtle 

 were examined. There was no food, but the mucous membrane of the 

 intestine as far as the rectum was thickly peppered with small, black 

 spots which proved to be small distomes. There were about 50 to the 

 square inch in a surface 18 inches long by 3 inches broad. The dark 

 color is due to the eggs which are collected in a mass at the posterior 

 end of the distome. Specimens which had lain in sea-water overnight 



