10 PROCEEDINGS OF THE NATIONAL MUSEUM vol. ui 



In the lumen of the genital antrum in one of the worms examined 

 (No. 460j), an undeposited cocoon was found. It was ovoid (0.8 x 0.5 

 mm) and a semitranslucent brown (pi. 1j). 5 



Remarks. — The taxonomy of the genus Phagocata Leidy, 1847 

 (=Fonticola Komarek, 1926) has been discussed heatedly by several 

 taxonomists such as de Beauchamp (1961), Dahm (1958), Darlington 

 (1959), Hyman (1937a,b; 1951a,b), Ichikawa and Kawakatsu (1962a, 

 b,c; 1963), Kenk (1930, 1935, 1944, 1953) and Kawakatsu (1965a). 

 The genus as presently defined has representatives in Europe, Asia, 

 and North America. 



The indubitable North American Phagocata species are as follows: 



Phagocata gracilis gracilis (Haldeman, 1840) from Pennsylvania 

 and Virginia westward to Missouri; P. g. woodworthi (Hyman, 1937a) 

 from New England westward to the Delaware River (transitional 

 forms between gracilis and woodworthi occur in New Jersey; see 

 Hyman 1945, 1951b); P. g. monopharyngea Hyman (1945) from 

 Iowa; P. velata (Stringer, 1909) from the Mississippi Valley, Michigan, 

 and Ontario westward to Nebraska (probably also Colorado and 

 southward into Missouri); P. vernalis Kenk (1944) from Michigan 

 (midcentral states) ; P. morgani (Stevens and Boring, 1906) from 

 the Appalachian region, Wisconsin, Michigan, and also Canada; 

 P. morgani polycelis Kenk (1935) from Virginia; P. bursaperforata 

 Darlington (1959) from Georgia; P. oregonensis Hyman (1963) from 

 Oregon; P. nivea Kenk (1953) from Alaska; P. subterranea Hyman 

 (1937b) from Donaldson's Cave and Mayfield's Cave of Indiana; 

 P. cavernicola Hyman (1954) from Evac Cave of Pennsylvania. In 

 these species (8 species and 4 subspecies) only P. subterranea and 

 P. cavernicola are cave-dwelling planarians and are known from the 

 subterranean waters in caves. The other species occur in epigean 

 waters. 



Externally, Phagocata nivea tahoena is readily distinguishable from 

 all other North American Phagocata species except three, P. velata, P. 

 vernalis, and P. gracilis monopharyngea, by the following points: size 

 and form of the body, pigmentation on the dorsal side of the body, 

 number of eyes, and number of pharynges. Anatomically, the arrange- 

 ment and number of the testes and the structure of the copulatory 

 apparatus of P. n. tahoena are distinctive. 



Phagocata nivea tahoena differs from the other members of the genus 

 in the following characters: small, up to 12 mm in the preserved 

 state; head truncate without auricles; eyes two; colored; testes small, 

 numerous, extending to the posterior end, lying ventrally; spermiducal 



5 After being photographed, the cocoon was mounted on a slide but unfortu- 

 nately shrank into ridges. The head piece (the posterior part of the body had 

 disintegrated) also was mounted on the same slide (No. 460j). 



