BRITISH MARINE TURBELLARIA. 467 



middle into long vermiform bodies, in which Jensen perceived 

 a central thread. The opening of the proboscis-sheath is 

 ventral, and close to the anterior end. The proboscis itself 

 is feebly muscular. The mouth is a transverse slit, surrounded 

 by an arcuate transverse row of six adhesive papillae. The 

 eyes, two on each side, lie over the brain behind the proboscis. 

 The genital pore is veutral, a short distance from the hinder 

 end. The vasa deferentia are given off from the two rounded 

 lateral testes. They unite along with the accessory secretion 

 at the base of the spirally coiled ejaculatory duct. This 

 consists usually of two coils and a terminal straight portion. 

 The spermotheca is armed anteriorly with chitinous spines; 

 posteriorly, according to Jensen, it communicates by a long 

 narrow duct with the genital atrium. (For figures see 

 Jensen's "Turbellaria Norvegise " [49], pi. iii, figs. 14 — 22.) 



Habitat. — Among Zostera, Plymouth Sound; tide-pools, 

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



Distribution. — Bergen (Jensen). 



27. Hyporhynchus penicillatus (Schmidt, 32). 



A young immature specimen that I refer rather doubtfully 

 to this species measured '6 mm. in length. Body of a bright 

 yellow colour, the pigment being deposited in fine granules 

 at the base of the epidermal cells. Rhabdites small, occur- 

 ring in numbers over the surface. The aperture of the 

 proboscis-sheath is triangular, ventral, close to the anterior 

 end. The eyes were fairly large, and provided with lenses. 

 The genital organs were not developed, hence the doubt 

 attaching to this example, which, however, in all remaining 

 characters agrees with H. penicillatus as described by v. 

 Graff. 



Habitat. — Among Zostera, Cawsand Bay, Plymouth (F. 

 W. G.). 



Distribution. — Lesina (Schmidt, 32), Messina, and Naples 

 (v. Graff). 



