502 



has one very thick, rounded, gloffy, white volution-, very 

 convex, and wrinkled tranfverfely, with a minute um.' 

 hilicus at the top, and fometimes only a future. 



Not having afcertained this to be truly Britijh, we' 

 cannot give it a diftinft place in this work. 



Animal a Terebella, of a buff-colour, vrith ten ciliated 

 rays, and a fub-funnel fhaped probofcis at one fide, of 

 the fame colour, with a brown margin, ciliated, hyaline. 



4. 

 Carin'ata, S. with a dull, opaque, white, fpiral fliell ; the outer 



whirl riling into a carinated ridge on the top ; the mid- 

 dle concave, fometimes pervious ; the interior volutions 

 inconfpicuous ; bafe a little fpreading : aperture round. 

 Size about half that of the 5. Spirorbis, from which it is 

 readily diftinguifhed, by the angulated (liapc of the ex- 

 terior whirl, which is formed like S. triquetra, but al- 

 ways regularly fpiral. 



This we found on old valves ol Area pilofa, with the 

 laft, in confiderable abundance ; and plentiful in Salcmob 

 bay, on Pinna ingens, and many other {hells, efpecially 

 Trochus cinerarius &nd parvus, unmixed with any other 

 fpecies. 



5. 

 CoRRUGATA. S- '^'■'''^^^'^ ^ ftrong, fpiral, white fhcll, roughened by 



tranfverfe wrinkles ; a fmall portion of the fecond volu- 

 tion 



