Helminth Fauna of the Dry Tortugas. 



29 



Dimensions of ova: 0.034 by 0.040; 0.037 by 0.030; 0.040 by 0.040. 



Thickness of shell 0.0034. 



Host, Caretta caretta : June 29, 1907, 12 specimens, in stomach. 



II. TREMATODES FROM FISH. 



MALACOTYLEA. 



FASCIOLIDiE. 



Comparative table of the AllocreadiincB described in this paper. 



Helicometra torta sp. nov. (Figs. 29-33.) 



Body oval or long oval, often folded or crumpled and yellowish 

 ;green in life; neck rather short in preserved specimens; ventral sucker 

 2 to 2.5 times the diameter of the oral sucker, usually with its aperture 

 longitudinal; oral sucker usually nearly circular in outline, but ventral 

 sucker in most cases longer than broad. There is a short prepharynx. 

 The pharynx is somewhat variable, in some cases about as broad as long, 

 in others cylindrical and much longer than broad. The esophagus is 

 slender and as long or longer than the pharynx. The intestinal rami 

 extend to the posterior end of the body. Reproductive aperture median, 

 near the posterior end of the pharynx. The cirrus-pouch passes dorsad 



