507 



Serpula vitrea. GmeJ. Syft. p.' 3746 ? 

 Turt, Lin. iv. p. 607. 

 Ellis Zoop/i. p. 37. 



S. with an irregular, pellucid, gloffy, white flieil, 

 always more or lefs fpiral ; fometimes lateral, with two 

 or three whirls ; in others the volutions turn upon each 

 other, with the aperture projefting upward, and not un- 

 frequently the fpires are unconnefted. Diameter half 

 a line. 



This is at once diftinguifhed from all other fpecies, by 

 its extremely fmooth, glofly, and vitreous appearance. 



It is by no means an uncommon (hell, but we believe 

 is peculiar to fome fpecies of Sertularia, efpecially S". 

 abietina, on which it is almofl: a conflant attendant ;* and 

 fometimes on 5. argentea : is gregarious and very nu- 

 merous on the branches of thofe Zoophytes, which are 

 thrown up on moft of our coafts, efpecially in the wefl: 

 of England : and we have been a (Tu red by Mr. Boys, 

 (who fent it to us by the name prefixed,) that it is not 

 lefs common on the coafl: of Kent, on 5. abietina. 



This, though fubjeft to much variety in fhape, will 

 be always found to turn its aperture towards the appa- 

 rent motion of the fun, and confequently is a hetero- 

 Jirophe (hell. 



T t t 2 Animal 



* Ellis fays this Sertularm "is frequently infefted with little minute 

 fliells, called Serpulas." 



