L.M.B.C. TURBELLARIA. (39 



lobster, but I have found them on the surface of weed- 

 covered stones between tide-marks. 



This species is not uncommon in tide-pools at Port 

 Erin, and is abundant at Millport and Plymouth. Youn^^ 

 specimens occur in tow-nettings taken near shore. 



19. Vorticerosauriculatitm,O.F. Miiller (PL XIII. fig. 25.) 

 Length 1*5 — 2 mm. Body elongate. The angles of the 



anterior margin are produced, in the expanded condition, 

 into a pair of slender tentacles, almost ^5 the length of the 

 body. They may, however, completely disappear during 

 contraction. The colour is due to violet, reticular, paren- 

 chymatous pigment which occupies the dorsal surface 

 (except the margins) and is continued as a narrow band 

 over the upper surface of the tentacles. The anatomy 

 resembles in detail that characteristic of Plagiostoma. 



This elegant form occurs in tide-pools at Port Erin. It 

 has been taken by v. Graff at Millport, and myself at 

 Plymouth. 



20. AUostomaj^cUlidum,!'. J. Y.Ben. {FlXlll,figs.Sl,S2.) 

 A few immature examples of this species occurred at 



Port Erin. The anterior sixth is marked off from the rest 

 of the body by a circular ciliated groove. The epidermis 

 contains large numbers of ''mucus-rods," which have 

 been considered as intermediate between the amorphous 

 secretion of a subepidermal gland, and the sharply-defined 

 rhabdites. All three are homologous, but differ in the 

 degree of consistency. 



The common genital pore is almost terminal at the 

 hinder end. The penis is muscular. It receives the vasa 

 deferentia and granule-gland in its upper proximal portion. 

 The oviducts (according to v. Graff), unite before opening 

 to the exterior. This species has been recorded from 

 Millport. 



