78 Papers from the Marine Biological Laboratory at Tortugas. 



anterior edge of the genital sucker, and the ample cirrus-pouch, inclosing 

 the large prostate, and, at its posterior end, the seminal vesicle, lies along 

 the right side of the genital sucker, and, extending back of it, curves to 

 the left, so that the posterior end of the pouch usually lies on the median 

 line behind the genital sucker. On the left side of the genital sucker is 

 the ample, muscular-walled metraterm which opens, along with the cirrus, 

 at the genital sucker. The single testis is relatively large and lies be- 

 hind the cirrus-pouch ; in flattened specimens it is crowded to the right 

 side. Immediately at its anterior border is the ovary which is smaller 

 than the testis and subglobular in shape. The seminal receptacle is 

 situated near the base of the cirrus-pouch. The vitelline glands are 

 rather compact, lobular masses lying at the margins in the middle of the 

 length of the body. A yolk-duct runs from each to the vicinity of the 

 seminal receptacle. The folds of the uterus are very voluminous and 

 lie on left side of body between the metraterm and left vitelline gland. 

 From this region they extend caudad, filling posterior half of body. The 

 ova were of fairly uniform size in all the specimens measured from the 

 different hosts in which this worm was found. 



Host, Hcevnulon niacrostomum: June 28, 1907, 2 fish, i trematode. 



Dimensions, life, flattened: Length 1.15; breadth 0.63: oral sucker 

 0.14; pharynx 0.04; genital sucker 0.12; ova 0.017 by o.oio. 



Host, Hcemulon phimieri: July 7, 1907, 14 fish, few trematodes, 

 from pyloric caeca. 



Dimensions, life: Length 0.87; breadth 0.27; oral sucker 0.06; 

 pharynx 0.02; genital sucker 0.03 (?) ; ova 0.017 by o.oio. 



Host, Hcemulon sciurus: 1907, Juh^ 7, 4 fish; July 12, 3 fish, few 

 trematodes. 



Dimensions, life, flattened: Length 0.84; breadth 0.39; oral sucker 

 0.08; pharynx 0.03; genital sucker 0.04 (?); ova 0.017 by 0.013. 



Genolopa truncata gen. et sp. nov. (Figs. 214-216.) 



Bod}' spinose, linear or long oval, variable, the anterior end usually 

 truncate, posterior end blunt or blunt-pointed; oral sucker relatively 

 large; pharynx close to oral sucker, though there appears to be a short 

 prepharynx; esophagus as long, or a little longer than pharynx. Genital 

 sucker a little in front of middle; cirrus spinose; cirrus-pouch and extrem- 

 ity of metraterm capacious; seminal vesicle inclosed in cirrus-pouch. 

 There is i testis, oval or subspherical, median, behind cirrus-pouch; 

 ovary on right side of testis and a little in advance of it. The vitelline 

 glands are compact bodies near the margin on a level with the cirrus- 

 pouch. The folds of the uterus fill up all the available space behind the 

 cirrus-pouch; ova small, short-oval or elliptical. 



This species resembles Monostomum. sp. from Orthopristis chrysop- 

 terus (Parasites of Fishes of Beaufort, Bull. U. S. Fish Commission, xxiv, 

 p. 379, fig. 223), but the ova are very different. In the Beaufort species 

 the longer diameter of the ova is three times that of the shorter. 



Host, Hcemulon plumieri: 



1906, July 8, I fish, i trematode. 



1907, July 5, 12 fish, I trematode; July 10, 12 fish, i trematode. 



