POLYCLADS OF THE EAST COAST PEARSE 



91 



The median stem of the enteron is readily seen extending from the 

 pharynx to near the posterior end of the body, but the twigs of the 

 four pairs of lateral branches cannot be made out well in the preserved 

 specimens available. 



The male genital aperture is close to the posterior margin of the 

 pharynx. The coiled vasa deferentia enter the male bursa near its 

 anterior end and may be seen to extend posteriorly about 0.8 mm on 

 either side. Oval testes about 0.05 mm long are scattered evenly 

 through the interior of the body from the pharynx posteriorly, 

 except in a zone about 0.5 mm wide about the margin. A prostate 

 gland is separate from the seminal vesicle. The female genital pore 

 is about 0.6 mm posterior to that of the male system. It is connected 

 with two uteri, which bend posteriorly and then anteriorly. 



Type. — U.S.N.M. no. 20193, from St. Vincent Bar, Apalachicola 

 Bay, Fla. ; collected June 25, 1935, by A. S. Pearse. 



Remarks. — Only two specimens of this species were collected. 

 These were pale, pellucid and had no pigment or distinctive color, 

 the body appearing whitish. 



Family PROSTHIOSTOMIDAE 

 Genus PROSTHIOSTOMUM Quatrefages 



PROSTHIOSTOMUM LOBATUM, new species 

 FiGUKE 34 



Body of living specimen slender; head rounded and wider than 

 body, which tapers toward the pointed posterior end ; three specimens 

 studied alive on December 2, 1935, measured IT by 2.7, 11 by 2.3, and 

 7 by 1 nun. Three preserved specimens show the following distances 

 (in millimeters) from the anterior end to various organs and openings: 



The last line shows that when the body is strongly contracted the 

 mouth may be brought in close proximity with the brain. The 

 sucker is often lobate in contracted specimens, as the figure shows. 

 This feature is used to give the specific name to the species. 



The eyes number about 106 in adult worms, but younger speci- 

 mens have been examined with 4, 12, 20, 22, 28, 40, 68, and 70. In 

 three favorable large specimens the number of eyes is as follows : 



