62 Papers from the Marine Biological Laboratory at Tortugas. 



The folds of the uterus are closely compacted. The lateral excretory 

 vessels appear to meet above the oral sucker. There does not appear 

 to be an upper lip, as is shown in Looss's various closely allied genera. 

 Fig. 139 is a sketch of a tangential section through the head and neck. 

 It shows the cirrus, portions of the seminal vesicle, prostate gland, 

 metraterm, cleft in front of ventral sucker, with its thickened muscular 

 wall at the inner end, an ovum in the common genital duct, oral sucker, 

 pharynx, intestine and excretory vessel. 



Host, Neomcenis griseus: July 4, 1908, 1 fish, 1 distome. 



Dimensions, life: Length 1.20; breadth 0.35; oral sucker 0.11; 

 pharynx 0.04; ventral sucker 0.28; ova 0.012 by 0.006. 



Host, Echeneis naucrates: June 24, 1907, 1 fish, 8 distomes. 



Host, Abudefduf saxatilis: July 7, 1907, 1 fish, 1 distome. 



Dimensions, life: Length 1.05; breadth 0.25; oral sucker 0.10; 

 pharynx 0.04; ventral sucker 0.16; ova 0.017 by 0.010. 



Host, Ocyurus chrysurus: July 12, 1907, 3 fish, 2 distomes. 



Dimensions, life: Length 1.26; breadth 0.40; oral sucker 0.10; 

 pharynx 0.06; ventral sucker 0.24; ova 0.016 by 0.011. 



Host, Chlorichthys bifasciatus: 



July 8, 1907, 1 fish, 1 distome, immature. 



Dimensions, life: Length 0.46; breadth 0.19; oral sucker 0.07; 

 pharynx 0.03; ventral sucker 0.11. 



The specific relations of this young distome are doubtful. There 

 is a distinct prepharynx represented in the sketch made at the time of 

 collecting. The specimen was lost. 



Sterrhurus fusiformis (Liihe). (Figs. 141-147.) 



The general appearance of this distome is much like that of the 

 species I have recorded under the name Distomum monticellii, but the 

 vitelline glands are more numerously and more deeply lobed than in 

 that species. It appears to agree closely with Lecithochiriwm fusiformis 

 Liihe (Zool. Anz. xxiv, p. 476, fig. 3). Looss refers this species to the 

 genus Sterrhurus Looss (Zool. Jahr., 1907, p. 143, figs. 52, 55, 56). 



Body in general fusiform, but very variable; pale red or flesh-color, 

 body reddish, neck translucent yellowish (a specimen which had been 

 lying under the cover-glass for 2 hours or more was pale greenish-yellow 

 by transmitted light) ; neck short, frequently arched or abruptly folded 

 ventrally on itself; ventral sucker rather more than twice the diameter 

 of the oral sucker; esophagus very short; pharynx contiguous to oral 

 sucker. The rami of the intestines may reach to the cephalic end of the 

 large excretory organ in the appendix. Genital aperture ventral to the 

 caudal end of the pharvnx; cirrus-pouch muscular, surrounded by large 

 prostatic cells; seminal vesicle at its caudal end irregularly pyriform, in 

 front of and dorsal to the ventral sucker. Testes 2, small, nearly trans- 

 versely placed and near the caudal border of the ventral sucker. Ovary 

 subglobular or oval, not lobed, situated about the middle of the length 

 of the body; vitelline glands adjacent to and behind the ovary, made 

 up of 7 slender-clavate branches uniting in an attenuated middle part. 

 There appear to be 7 of these branches, 4 on the right and 3 on the left 



