POLYCLADS OF THE ATLANTIC COAST — HYMAN 489 



Distribution. — Florida to North Carolina. 



Habits. — Restless, changeable, on wharf pilings associated with 

 ascidians on which it feeds ; also on shells in shallow water. 



Remarks. — An examination of the type specimens of Oligoclado 

 ■floridanus and Hymania pinjthei'chi as well as of a number of other 

 whole mounts labeled with these names, together with some sets of 

 serial sections, has shown that the two species are identical and hence 

 H. prytherchi becomes a synonym of O. ■flo7'ida7ius. This species is 

 close to Eurylepta (not to Oligocladus as supposed by Pearse) and 

 in fact differs from Eurylepta only in the presence of a pair of uterine 

 ducts, which extend from the uterine glands to a common pore in the 

 rear part of the body. It must be emphasized, however, that these 

 ducts and the pore are present only in the largest, maturest specimens, 

 and individuals that have uteri full of eggs and masses of sperm in 

 the vasa deferentia still may show no traces of them. They apparently 

 appear only when breeding is at its height. Now it is quite possible 

 that these structures also exist in Eui'ylepta and have been overlooked 

 through a lack of fully ripe material. In fact, it must be admitted 

 that the available descriptions and figures of the reproductive system 

 of species of Eurylepta are none too satisfactory. I therefore feel that 

 the genus Oligoclado does not as yet rest on a firm basis. 



Genus ACEROTISA Strand, 1928 

 AceroH Lang, 1884. 



Definition. — Euryleptidae without tentacles, with a pair of eye 

 groups on the anterior margin in the sites of tentacles; with paired 

 cerebral eye clusters of few eyes ; male apparatus typically euryleptid ; 

 small to minute forms. 



ACEROTISA BAIAE, new species 



Figure 31, d. 



Material. — One whole mount in Pearse collection, slide No. 430, 

 labeled Prosthiostomum lohatumf^ cut into serial sections; in very bad 

 condition. 



Form.—RovighXy oblong (fig. 31, d) 3.2 mm. long by 1.8 mm. wide, 

 preserved; without tentacles; sucker could not be found. 



Eyes. — Pair of eye clusters on anterior margin, each cluster of about 

 4 or 5 larger eyes and several very small ones (fig. 31, d) \ cerebral 

 groups consist each of two large eyes, with one or two small ones. 



Gol<yi\ — ^Unknown. 



Digestive ^rac?^.— Typical bell-shaped pharynx in usual anterior 

 position, directed forward, torn from its attachment (fig. 31, d) ; 

 intestinal branches could not be discerned. 



