BYNE : MARINE MOLLUSCA OF TEIGNMOUTH. 1 83 



Skenea planorbis Fabr. Is a scarce shell alive, owing, 

 perhaps, to the difficulty of obtaining the weed in which 

 it dwells. Dead examples from drift. 



Caecum trachea Mont. Dead specimens dredged. 



C. glabrum Mont. From drift. 



Turritella terebra L. From rough ground, the bay being 

 full of them. A fine white form has also been dredged. 



Scalaria turtonae Turt. Nine specimens dredged alive, 

 this being the first occasion. Frequently trawled dead, 

 and found more or less imperfect on the beach. This 

 species seems to be more widely distributed than S. 

 communis. 



S. communis Lmk. Dredged on rough ground among T. 

 terebra. One fine live adult, one small dead specimen, 

 and one from drift. 



Aclis unica Mont. One fresh example in diift. 



Odostomia nivosa Mont. Alive on weeds trawled in the 

 bay. 



O. clavula Lov. One dead example dredged. 



O. rissoides Han. On isolated rocks on low tides, more or 

 less covered with stunted mussels. This species has been, 

 and is still to be, found living in colonies amongst and 

 underneath the mussels, to whose excreta they may be 

 attracted for existence. The Odostomice are not outwardly 

 visible to the naked eye, but swarm on the removal of the 

 mussels, or on being disturbed. A large dish piled up 

 with a quantity of the mussels for examination, produced, 

 after eleven days' picking off with a long hair pin, nearly 

 two egg cups full of O. rissoides., consisting of adults of 

 remarkable size down to the most minute. They perched 

 themselves upright and spire downwards wherever moisture 

 remained on the daily lessened quantity of mussels. They 

 were very active, and shifted quarters if they were dis- 

 turbed. If there were any doubt of this being a new 

 habitat for the species, the fact of many of the adults 



