448 r. W. GAMBLE. 



7. CoNVOLUTA FLAviBACiLLUM, Jensen. 



Length 2 — 3 mm. Body stout, oval, pointed behind, 

 dorsal surface convex, ventral surface flat. The margins are 

 produced into thin lamellse, flexed ventrally. Colour yellow, 

 due to the prevalence of pigmented yellowish-green rods over 

 irregular brown granules. Epidermis, flagella, and 

 rhabdites are similar to those of C. paradoxa. Eyes two, 

 reddish, placed on each side of the otolith. Female 

 genital pore situated at one-third the length of the body 

 from the hinder end ; halfway between the latter and the 

 pore is the male aperture. The chitinous raouth-piece of the 

 spermotheca is cylindrical, and composed of a number of 

 perforated plates placed one upon another. The spermatozoa 

 are elongate, tapering at each end, with a granular central 

 portion and clear lateral membranes. Penis cylindrical, 

 muscular. 



Habitat. — Among Larainaria, &c., Millport (v. Graff) ; 

 among sand at base of Corallina officinalis in tide-pools, 

 Port Erin, Isle of Man ; Plymouth (F. W. G.). 



Distribution. — Bergen (Jensen). 



The stout form and yellow colour sufficiently serve to 

 distinguish this species, which, in its anatomy, closely resembles 

 Convoluta paradoxa. 



B. BHABDOCCELA. 



Gut and parenchyma distinct. A spacious body- 

 cavity usually present. Nervous and excretory 

 organs present. Gonads hermaphrodite (except 

 Microstoma and possibly Stenostoma). Testes 

 usually compact, and ovaries, germ -yolk-gland, or 

 separate vitellaria and germaria may be present; 

 in all cases surrounded by a tunica propria. 

 Pharynx present, variable. Otolith usually 

 absent. 



