376 SUPPLEMENTARY NOTES. 



mation and sketches of the animal from Mr. Cocks, of Falmouth. 

 According to that excellent observer, the siphon is single and the 

 anal aperture opens about one-third from the base. Crested 

 ridges with pectinated edges, run from the root of the siphon to 

 its extremity. The natural length of the siphon of one kept 

 alive by Mr. Cocks, was one inch and a quarter. We shall give 

 a fresh figure. In the body of the work, as well as upon the 

 plate itself, the representation of that variety of Astarte Dan- 

 moniensis, which has a red interior (xxx. f. 5), is erroneously 

 assigned to A. triangularis. 



In a note at page 45 of vol. i., the genus Clausina of Jeffreys 

 is stated to have been arranged by Mr. Gray among his Tcllinidce. 

 This is a mistake ; Mr. Gray placed it in his Lasiaclce and next to 

 Montacuta ; a position by no means unnatural. In our descrip- 

 tions of the Montacutce, the longer side of the shell is, by an over- 

 sight, described as the posterior extremity, which is contrary to the 

 more correct statement put forward in the account of the animals. 

 Since the commencement of our work, several important papers 

 have been published bearing on this part of our subject, such as 

 the memoir of M. de Quatrefages on Teredo, the controversy on 

 Kellia between Mr. Alder and Mr. Clark, &c. ; but on these and 

 other points we reserve our notes until the conclusion of the 

 work. 



