370 Zoological Society. 



LiTHODOMUS CANALiFERUs. Lit. testd elongato-oblotiffd, suhcy- 

 lindraced, recta, leevigatd, epidermide castaned siib tegmine calcareo 

 indutd ; tegmine in lineis elevatis, crassis, radiantibus , superneque 

 opertis, antice ordinato ; sulco obliquo ex umbonibus ud marginem 

 ventralem subrectum et lev iter convexiusculum, unticc decurrente ; 

 margine cardinali subincurvato, elongato, leviter elevato ; antico 

 dorsali, subrecto ; extremitate untied obtusissimd, posiicd vix an- 

 gustatd. Long 0"65 ; lat. 2. 

 Hub. Found in rocks, isle of Zebu. Mus. Cuming, Hanley. 

 At once recognisable by the extraordinary arrangement of its 

 calcareous coating over the umbonal slope, on which are placed three 

 oblique covered canals, formed by four radiating ridges, with another 

 coating of calcareous matter spread above them, leaving the aper- 

 tures distinctly visible at the anterior extremity. 



LiTHODOMUS PLTJMULA. Lit. tcstd L. canalifcro simillimd, sed ex- 

 tremitate untied minus obtusd ; tegmine culcareo antico, crassiore, 

 atqiie in parietibus confertis, subpurallelis ordinato ; parietibus 

 corrugatis et {plumvlce hand dissimilibus) versus marginem ven- 

 tralem et marginem anticum utroqne latere radiantibus. Long. 

 075 ; lat. S'So. 

 Hab. Panama, in Spondyli. Mus. Cuming, Hanley. 

 Were it not for the calcareous coating of the umbonal ridge, this 

 curious shell could scarcely be discriminated from the preceding 

 species. This coating is of a cellular structure, and is composed of 

 numerous rather elevated narrow ridges, which slope for^vard, and 

 so radiate on either side from the middle as to remind us of a ruffled 

 feather. 



Mytilus granulatus. Myt. testd parvd, ovali-triangulari, tumidd, 

 crassd, radiatim costulatd ; costis distinctis, atigustioribus, rotun- 

 datis, granulatis, plerumque bifurcatis ; epidermide ochraceo- 

 jiavescente ; margine cardinali brevi, convexo ; antico valde ar- 

 cuato, dilatuto ; ventrali subincurvato ; tiatibns maxime incumben- 

 tibus divaricatis ; angulo dorsali rotundato ; latere postico planulato, 

 valde tumido ; superficie internd albd, sub?nargaritaced ; jnargine 

 interno cremdis dentato. Long. 0'50; lat. 0"75. 

 Hab. Valparaiso, under stones at low water. Mus. Cuming, Met- 

 calfe, Hanley. 



A species easily to be distinguished by its narrow granulated ribs 

 (which become still narrower on the flattened posterior slope) and 

 by the peculiarity' of its beaks, which slope so greatly back as to 

 cause the shell to appear blunt and almost truncated at that part. 

 The hinge, as in most of this genus, is provided with two teeth in 

 one valve, and one in the other. 



" A description of new species of recent Shells," chiefly from the 

 collection of W. Metcalfe, Esq. 



Amphidksma scabrum. Amph. testd obovatd, convexd, solidd, sub' 

 cequilaterali, albd, lineis rubro-castaneis radiutd, concentrice lamel- 

 liferd ; lamellis brevibus, tenuibus confertis, interstitiis minutis- 



