480 F. W. GAMBLE. 



be considered provisional. Already Enterostoma striatum, 

 V. Graff, has been investigated, with the result that Bohmig 

 places it under the sub-family Cylindrostominae (loc. cit., 

 p. 469), and similar change in species hitherto considered as 

 belonging to the Allostominse may be expected to result 

 from detailed investigations. 



Genus 19. — Enterostoma, Claparede (35). 



Allostominae with uniformly ciliated body and with- 

 out a circular "ciliated groove" on the head. 



44. Enterostoma austriacum, v. GraflF. PI. XXXIX, fig. 7. 



Length "75 mm. Body rounded anteriorly, tapering to a 

 blunt "tail" behind. Colour usually yellow, with a black 

 spot (due to the intestine) in the centre ; occasionally the 

 general colour is white, the gut being yellow. The colour of 

 the surface is due to the presence of yellow granules in the 

 epidermis ; that of the gut to its contents. The yellow epi- 

 dermal granules are massed together in small heaps, which are 

 not so conspicuous or large as figured by v. Graff (pi. xix, 

 fig. 9, Monograph). Exceedingly small, slender rhabdites 

 are present in groups in the epidermis. The pharynx is 

 cylindrical, very muscular, and is inserted at the hinder edge 

 of the extensive gut, which, following the outline of the body, 

 reaches as far forward as the brain. The eyes are arranged in 

 two pairs, an anterior and a posterior pair. The former are 

 slightly the smaller, and their lenses are directed outwards 

 and backwards ; the lenses of the posterior pair face forwards 

 and outwards. The genital aperture is a short distance 

 from the hinder extremity. Round the brain are the de- 

 veloping testes. The pyriform muscular penis lies behind 

 the pharynx. 



Habitat.— In 4 — 18 fms., Plymouth and Port Erin (P. 

 W. G.). 



Distribution. — Trieste (v. Graff). 



