BRITISH MAEINE TURBELLARTA. 481 



45. Enterostoma fingalianum, Claparede (35). 



Length 1 mm. Body elongate, cylindrical, rounded at 

 both ends. Colour white; the short, almost central gut 

 reddish. The epidermis contains small fusiform rhabdites, 

 figured by Hallez (50, pi. ii, fig. 25). Mouth at the 

 commencement of the posterior third. Pharynx cylindrical, 

 at the hinder margin of the intestine. Brain bilobed. Eyes 

 fairly large, arranged as in En t. austriacum. Genital pore 

 between the mouth and the hinder end. Testes numerous, 

 surrounding the brain. Vasa deferentia exhibit dilatations 

 along their course. Penis pyriforna, containing masses of 

 accessory secretion in its basal portion ; provided at its tip 

 with small papillse. Claparede's original description and figures 

 are not sufl&ciently distinctive to enable us to determine 

 whether the germ- and yolk-glands are distinct or not. In 

 my specimen the yolk-glands form lateral masses uniting 

 behind the brain, and again posteriorly behind the genital 

 aperture. The germ-glands lie at the sides of the pharynx, 

 and appear to be separate from the yolk-glands. As, however, 

 only a single specimen was available, further observations are 

 greatly needed on this and other points, such as the presence 

 of a ciliated ''head-furrow " (which Bohmig has demonstrated 

 in other forms by the use of methylene-blue in cases where 

 superficial observation had previously failed) and the possible 

 connection of genital and oral apertures. 



Habitat. — Skye (Claparede) ; among Balanus, 10 fms., 

 Plymouth Sound (F. W. G.). 



Distribution. — Wimmereux (Hallez). 



46. Enterostoma ccecum, v. Graff". 



Length 17 mm. Body gradually tapering forwards from 

 the hinder end. Beneath the epidermis are yellowish-green 

 granules, especially abundant at the sides. The pharynx is 

 cylindrical, muscular, placed far posteriorly. The sperma- 

 tozoa consist of a central rib bearing lateral membranes, and 



