42 Papers from the Marine Biological Laboratory at Tortugas. 



1908, June 30, 3 fish, 25 distomes; July i, i fish, 12 distomes; July 

 4, II fish, 2 distomes; July 11, i fish, 4 distomes; July 14, i fish, 

 2 distomes; July 15,1 fish, 5 distomes. 

 Color in life translucent white tinged with yellowish-green. 

 Dimensions, life, slightly flattened: Length 0.92; breadth, anterior 

 0.21, near posterior 0.50; oral sucker 0.18; pharynx 0.07; ventral sucker 

 0.16; ova 0.048 by 0.031. 



Host, Calamus calamus: July 6, 1907, i fish, i distome. 



Lepocreadium levenseni (Linton). (Figs. 75-77.) 



Distomum levenseni, Linton, Proc. U. S. Nat. Mus., xxxiii, p. no, plate xii, 

 figs. 80-83. 



Certain distomes from Tortugas groupers are here recorded. 



One of them, from Epinephelus striatus, agrees with D. levenseni 

 in every essential particular. The cirrus-pouch is long and passes on 

 the left side of the ventral sucker. It includes the voluminous, tubular 

 seminal vesicle in its basal portion which lies along the median line 

 behind the ventral sucker. The muscular excretory bulb is conspicuous. 



Dimensions, life: Length 1.58; breadth, anterior 0.16, middle 0.49, 

 posterior 0.28; oral sucker o.ii ; pharynx 0.07; ventral sucker 0.12; ova 

 0.068 and 0.040. A larger specimen measured 2.75 mm. in length. 



Dimensions of a specimen mounted in balsam: Length 1.96; breadth 

 0.46; neck 0.50; oral sucker, length 0.12, breadth 0.14; pharynx, length 

 0.07, breadth 0.05; ventral sucker o.ii ; ova 0.06 by 0.034. 



Three distomes, from Epinephelus morio and Mycteroperca venen- 

 vsa, while quite incomplete in that neither cirrus-pouch nor genital aper- 

 ture could be made out and they may indeed represent different species, 

 are referred to this species provisionally. Thus it is probable that the 

 ■distome from Mycteroperca is specifically different from those found in 

 Epinephelus, but on account of the meagerness in the amount of material, 

 and also in view of the fact that there seems to be a considerable range 

 of variation in this species as seen in the material collected from the 

 Bermuda groupers, it would be inadvisable to give to this lot definite 

 specific position at present. In the specimen from Epinephelus (fig. 75) 

 the oral sucker was invaginated. The relative size and position of the 

 suckers agree with D. levenseni. The pharynx is relatively larger and 

 the vitellaria extend nearly to the bifurcation of the intestine. This 

 latter fact might justify placing them in a different species. There is a 

 distinct esophagus and the thick-walled intestines extend to the posterior 

 end. The relative positions of testes, ovary, seminal receptacle, and 

 uterus agree with the Bermuda specimens. There is a globular, muscular 

 bulb at the excretory pore, as in D. levenseni. 



In the specimen from Mycteroperca (fig. 77) the same resemblances 

 and differences, when referred to D. levenseni, prevail as in the specimens 

 from Epinephelus. In addition the ventral sucker is situated relatively 

 farther from the anterior end, although in this specimen the oral sucker 

 is not invaginated, so that the neck is not shortened as it is in the speci- 

 mens from Epinephelus. In all the specimens the general outline of the 

 body and the investment of spines are as in D. levenseni. 



