57 

 Genus Amphidesma. 



Amphidesma pulchrum. Amph. testd ovali, pallidd, superficie 

 concentrice striatd ; intus albidd, purpureo-varid ; latere postico 

 breviore ; margine anticd inclinatd, striis nonnullis radiantibus, 

 strias incrementi decussantibus : long. l^'o, lat. ^\, alt. 1 poli. 



Hab. in Sinu Caraccensi, Americae Meridionalis. 



This species resembles Amph. variegaium, Lam., in form j it is 

 white vvithin, very prettily mottled with purple. — G, B. S. 



Genus Mabginella. 



Marginella Ctpr^ola. Marg. testd ovali, asperd, purpureo-ni- 

 gricante ; spird brevissimd, obtusd ; anfractu ultimo superni ven- 

 tricoso, lined dorsali Icevi ; labio externo incrassato, involuto, intils 

 denticulato ; labio columellari traiisversim plicato : long, -^, lat. 

 iV poli. 

 Hab. sub lapidibus et in locis arenosis ad littora Acapulcae et 



Sanctae Elenae. 

 A most interesting species, inasmuch as it appears to be the link 

 connecting Marginella vvith Cyprcea : though covered nearly all over 

 vvith a fine asperity, it has nevertheless a polished surface ; the spire 

 is very sniall, and the mantle of the animal mušt have been almost 

 equal on both sides, since there is a nearly centrai dorsal line which 

 is quite smooth and free from the asperity which covers the remainder 

 of the lašt volution. — G. B. S, 



Marginella Frumentum. Marg. testd ovali, politd, pallescente, 

 lineis undulatis per series tres dispositis pieta ; spird retusd, aper- 

 turd longitudine testą ^ peritremate acuto, lavi ; columelld infra. 

 plicis nonnullis: long. -rw, lat. i'u, paulo niitiits, poli. 

 Hab. ad oras Americse Meridionalis. (St. Elena and Salango.) 

 A very pretty little species, dredged in from eight to ten fathoms 

 with a sandy bottom. — G. B. S. 



Genus Chiton. 

 * Ligamento marginis Isevi. 

 Chiton pusillus. Chit. testd miniind, obovatd, albicante ; dorso 

 elevato ; valvis intermediis angustis, minutissime punctulatis, areis 

 lateralibus subdistinctis ; valvd posticd majori, vertice centrali, 

 postice inclinato : long. ■^, lat. -rV poli. 

 Hab. ad littora Peruviae. (Pacasmayo.) 



Distinguished from all the other Chitons by the comparative height 

 and proportions of the posterior valve, which has a centrai verte.v in- 

 clined backvvards. 



Found on a coral reef in seventeen fathoms vvater nine miles from 

 land.— G. B. S. 



Chiton Grayii. Chit. testd oblongd, pallidd, rufescente fuscogue 

 varid į valvd anticd, valvarum intennediarum areis lateralibus et 

 valvcE posticce ared posticd radiatim granoso-striatis ; arearum la- 

 teralium marginibus anticis elevatis, posticis crenulatis ; valvarum 

 intermediarum areis centralibus et valvcc posticce ared anticd ob- 



