Chitones. 99 



to by LinnaeuSj represents a shell with a scaly margin, as I have 

 liiyself had an opportunity of ascertaining. I am much inclined 

 however to consider Turton's shell as a more accurately observed 

 specimen of C. IcBvis* Amongst my specimens there is one which 

 being a good deal decorticated in some places, shews immediately 

 under the outer granulated layer an internal shelly coat of a 

 porous or reticulated structure, resembling the punctured part of 

 a thimble.* Without further data I have not ventured to deter- 

 mine this question, but trust these observations will lead to some 

 elucidation of the point from others more competent to decide. 



C. septemvalvis of Montagu if not a distinct species, being des- 

 cribed with a reticulated margin, ought certainly to be referred 

 to this rather than to C marginatus. 



The synonymes of this very distinct species have been united 

 by Mr. Dillwyn with those of C. cinereus, of which he considers 

 it merely a variety. The only way of accounting for this, is 

 by supposing he mistook it for the reddish variety mentioned by 

 authors of C» cinereus^ or perhaps C ruber of this paper ; and 

 that he was not in possession of the true C. Iccvis, His refer- 

 ence to Adanson, t. 2, f. 11, p. 42, must certainly be expunged. 

 The shell there represented is probably C. fascicular is, 



*** LiGAMENTO MARGINIS RUGOSO, SC. FARINOSO AUT GRANULOSO. 



3. Chiton cinereus. 



C. testa carinata, ovata ; vulvulis regulariter granulatis ; mar- 

 gini farinoso, distincte fimbriato. 



Valvuli medii dentibus 2 suboequalibus utrinque. 

 Valvulus primus dentibus circiter 10; ultimus 12. 



Icon. Chemn. Conch. 8. t. 96. f. 818.— Barn. Test. Mus. Cccs. 

 p. 5. t. 1. f. 3. (fide Chemn).— Wood's Gen. Conch, p. 3. f. 4. 

 (referred to in the text for C. marginatus). — Dorset Cat. pi. 1. 

 f. 4. — Encyc. Meth. pi. 161. f. 11. (wo/e, the valves not 

 beaked). 



* I have since observed the same appearance in a very young decorticated 

 specimen of C. latus. May it not be commoii to all the species ? 



g2 



