38 Papers from the Marine Biological Laboratory at Tortugas. 



Host, Anisotremus virginicus: July 6, 1907, i fish, 2 distomes. 

 Dimensions in balsam: Length 1.29; breadth 0.59; neck 0.48; oral 

 sucker 0.17; pharynx 0.07; ventral sucker 0.31 ; ova 0.041 by 0.027. 



Lebouria crassigula sp. nov. (Fig. 60.) 



This species resembles Lebouria idonea Nicol, but the habit is more 

 stocky than in that species, and the dense vitellaria meet in front of the 

 intestinal bifurcation. 



Body short oval or oval-elliptical; diameter of ventral sucker 1.25 

 to 1.33 times that of the oral sucker; pharynx relatively large; esophagus 

 apparentl}^ very short ; intestinal rami not distinctly seen but appear to 

 reach to the posterior end ; genital aperture a short distance in front of the 

 ventral sucker on left side of the median line ; cirrus-pouch nearly cylin- 

 drical, lying along the anterior and right antero-lateral border of the ven- 

 tral sucker, the seminal vesicle being included in its basal portion ; pros- 

 tate cells few, mainly anterior to the seminal vesicle; metraterm on left 

 side of the cirrus-pouch. Testes 2, near together on the median line, 

 little if any diagonal, and near the posterior end of the body, oval. 

 Ovary oval, on right side of the median line a short distance in front of 

 the testes; seminal receptacle dorsal to the ovary and projecting caudad 

 of its posterior border; vitelline glands very dense, obscuring the intes- 

 tines, posterior and lateral, extending forward to the posterior edge of the 

 oral sucker and meeting in front of the intestinal bifurcation ; uterus 

 between testes and ventral sucker; ova large. 



Host, Calamus calamus: 



1907, July 6, I fish, i distome, immature. 



1908, June 28, 2 fish, i distome; July 8, 5 fish, 2 distomes. 

 Dimensions, life: Length 1.54; breadth 0.66; oral sucker 0.25; phar- 

 ynx 0.15; ventral sucker 0.35; ova 0.068 by 0.040. 



Dimensions of another, in balsam: Length 1.33, breadth 0.52, neck 

 0.53; oral sucker 0.24; pharynx 0.15; ventral sucker 0.27; ova 0.07 by 

 0.04. 



Megasolena estrix gen. et sp. nov. (Fig. 64.) 



Etymology: I'-^y"-^, large; TtDkr^'^. pipe. 



Body nearly linear in outline, tapering slightly-^at posterior end and 

 abruptly truncate anteriorly. Mouth nearly terminal, oral sucker and 

 pharynx about same size and each larger than the ventral sucker. The 

 musculature of the ventral sucker is weak, while that of the oral sucker 

 and pharynx is strong. Genital aperture in front of ventral sucker; 

 cirrus-pouch with relatively thick wall and inclosing the short cirrus and 

 seminal receptacle. It lies in front of the ventral sucker. The prostate 

 lies alongside the cirrus-pouch and extends posteriori}^ on the right side 

 of the ventral sucker. The cirrus-pouch is contiguous with the anterior 

 border and the prostate extends to about the middle of the ventral 

 sucker. There is a distinct prepharynx and an esophagus which is 

 longer than the pharynx. The bifurcation of the intestine is dorsal to the 

 ventral sucker and the rami extend to the posterior end. The prephar- 

 ynx, pharynx, esophagus, and intestines are all relatively large. The 



