484 PROCEEDINGS OF THE NATIONAL MUSEUM vol.89 



for dorsal view see Pearse's figure 33). Differs from E. spinifera 

 in that there is a single pair of uteri, whereas latter has two pairs. 



Distribution. — St. Vincent Bar, Apalachicola Bay, Fla. 



Habits. — Not stated by Pearse. 



Remarks. — Pearse regarded this species as a cotylean and there- 

 fore attributed to it a sucker, marginal eyes, and a prostate vesicle, 

 which do not exist; he entirely overlooked the marginal spines. 

 This species is so similar to the only other known species of the 

 genus and family, E. spinifera Graff (1890), that it may be placed 

 without hesitation in that genus. Distinctions from E. spinifera 

 are noted above. 



Suborder COTYLEA 



Definition. — Polyclads with a sucker behind the female genital 

 pore; tentacles when present of the marginal type; eyes on anterior 

 margin in two groups, extending on tentacles when present; or eyes 

 in a band along anterior margin; pharynx ruffled to tubular; uteri 

 usually behind female genital pore; prostate when present always 

 free; Lang's vesicle absent. 



Family PSEUDOCERIDAE Lang, 1884 



Defvnition. — Cotylea of considerable size and oval shape; tentacles 

 broad and blunt, formed of marginal folds, bearing eyes; pharynx 

 ruffled; gut branches numerous and anastomosed; male copulatory 

 apparatus single or double, with a penis stylet and free prostatic 

 vesicle; uteri branched; uterine glands often present. 



Genus THYSANOZOON Grube, 1840 



Definition. — Pseudoceridae in which the dorsal surface bears nu- 

 merous papillae each of which contains a gut branch ; male apparatus 

 double (paired). 



THYSANOZOON NIGRUM Girard, 1851 



Thysanozoon nigrum Gibard, 1851, p. 137. 



Material. — Two specimens taken alive at Bermuda. 



Form. — Elongated-oval shape, narrowing at anterior end to the 

 two projecting marginal tentacles; dorsal surface with numerous 

 papillae with rounded tips; 25-30 mm. long, 8 mm. wide when 

 extended in locomotion. 



Eyes. — Rounded cluster of cerebral eyes in median line just in 

 front of anterior end of pharynx ; eyes on tentacles indistinguishable 

 because of black color. 



Color. — Velvety black above; may have a few white flecks; dusky 

 below. 



