Helminth Fauna of the Dry Tortugas. 53 



yolk-gland and there is a \'olk-reservoir on the dorsal side of the ovary. 

 The folds of the uterus are most abundant between the ovary and testes, 

 although the uterus begins at the caudal border of the yolk-glands and 

 the folds extend to the ventral sucker, whence the metraterm traverses 

 the neck to the reproductive aperture. The excretory vessel is slightly 

 enlarged at the posterior end near the excretory pore. It is a single 

 ventral vessel thence to a point about on a level with the anterior testis, 

 where it divides, the two branches passing forwards laterally to unite 

 above the'pharynx. Length 2 to 5.5 mm. 

 Host, Teuthis hepatus: 



1907, July I, I fish, 12 distomes. 



Two of the distomes from this host, collected on this date, were 

 apparently macerated. The reproductive organs were mere vestiges. 

 The bodies were filled with ova associated with black pigment. Bodies 

 cylindrical, neck short. While the details of structure are too meager 

 to permit of identification the distomes are probably near this species. 



Dimensions of larger, life: Length 5 ; oral sucker 0.22 ; pharynx 0.14 ; 

 ventral sucker 0.50; ova 0.027 by 0.015. 



1908, July II, I fish, 3 distomes; July 11,3 fish, 3 distomes; July 14, 

 3 fish, 7 distomes ; July 15, i fish, 3 distomes. 



Bright red by reflected, yellow by transmitted light; irregular 

 cylindrical, more or less contorted. 



Dimensions, life, flattened: Length 4.5; breadth 0.73; oral sucker 

 0.23; pharynx o.io; length of ventral sucker 0.70; ova 0.027 by 0.017. 

 The surface of some specimens was nodular, especially on the neck. 



Host, Teuthis car id ens: 



1908, June 27, I fish, 2 distomes; July 5, i fish, i distome; July 10, 

 I fish, I distome. 



Pale red, intestines black. 



Dimensions, life, flattened: Length 5.5; breadth, anterior 0.32, at 

 ventral sucker 0.92, behind ventral sucker 0.65, posterior 0.28; oral 

 sucker 0.28; pharynx 0.15; ventral sucker 0.77; ova 0.030 by 0.015. 



Macradena perfecta gen. et sp. nov. (Figs. 118, 119.) 



Etymology: p-uk/xj^, long; dihj'^, gland. 



The following notes are based on a series of longitudinal horizontal 

 sections, and a few transverse sections, the greater part of the trans- 

 verse series having been lost by accident. 



Body crossed by fine ruga?, linear, tapering very slightly at the ex- 

 tremities ; neck between one-fifth and one-sixth the entire length ; mouth 

 ventral; esophagus very short; reproductive aperture about on a level 

 with caudal end of pharynx; cirrus-pouch long, cirrus short, prostatic 

 portion long and slender, extending 0.3 mm. caudad of the ventral 

 sucker. The seminal vesicle is at the caudal end of the prostate and 

 beside the anterior testis. The testes are ovate, their longer axes trans- 

 verse to the long axis of the body. They lie close together one behind 

 the other. The ovary, which in some of these sections appears to be 

 2-lobed, is near the caudal border of posterior testis. The outline of the 



