573 



DONAX. 



The animal inliabitant of this fliell is an Afcidia, and Ikus. 

 not a Tethys ; which is probably the cafe with moll fuch ?• lOS. 

 whofe nature it is to perforate other bodies : it has two 

 flender, pellucid, white tubes, fpotted with opaque 

 white ; thefe are not half fo long as the (hell, and joined 

 together, except near the end, where they diverge, and 

 become of a pink colour, the openings ciliated with 

 feathered fibres of the fame: in fome the points and 

 fringe are of the fame colour as the reft of the tubes. 



D, with a ftrong, glolfy, chefnut-coloured fliell, ftir-c^^jxANEA, 

 nifhed with a few irregular, tranfverfe, antiquated ridges, 

 or wrinkles ; one fingle ray of the fame colour, but 

 darker, runs from the beak to the oppofite margin, in a 

 curved direftion, and divides each valve nearly in equal 

 parts; from this to the pofterior end the colour becomes 

 pale: mw^o obtufe, rather inclining to the anterior, or 

 longeft fide. Infide of the fame colour, fmooth and glof- 

 {y, with a fmall trace of the ray at the margin : hinge 

 very ftrong; teeth, one very large, and one fmall, in 

 each valve; no lateral teeth: cicatrix broad, running 

 from the anterior fide one third acrofs the fliell, in a 

 tranfverfe direftion, from which continues a marginal 

 line almoft to the oppofite fide: margin plain. Length 

 a quarter of an inch; breadth three-eighihs. 



This 



