500, 



found on feme fpecics of algce, feklom on flones, fhells, 

 or cruftaceous animals, like the laft, and rarely, if ever, 

 in company with that (lielL 



On the Corallina officinalis, from Milton rocks, is 

 found in great abundance, a minute fpecies of Serpula, 

 differing fo little from 5. Spirillum, except in fize, that 

 we dare not give it a diflinft place, though we are in- 

 clined to think it is really different, as it never grows 

 above one third the fize of that fiiell. Although this is 

 found to inhabit the fame fpecies of Zoophyta as S. minu- 

 ta, yet they are rarely found together. 



This very intricate clafs of fhells requires a thorough 

 knowledge of their animal inhabitants ; and which, in 

 the fmaller fpecies, is attended wuh a confiderable dif- 

 ficulty, for even when coUefted, put into fea water im- 

 mediately, and examined upon the fpot, few appear to 

 protrude themfelves fufficiently for critical notice: in- 

 deed it muft be admitted, many of the fpiral kind are in- 

 habited by animals of very fimilar appearance. 



S. 



Granulata. Serpula granulata. Gmel. Syji p. 3741. 



Tiirt. Lin. iv. p. 604. 

 Don. Br. Shells, iii. t. 100. 

 Serpula fulcata. Lin. Trans, iii. p. 254. (Adavis,) 

 Turt. Liu. iv. p. 60S. 



S. witli 



