PTEROCERA. 



Genus PTEROCERA, Lamarck. 

 Testa ovcdo-oblonga, veniricosa, spirii phis minus acuminata, 

 anfractti tiliimo valde majore, labro in alam digitatam 

 ampUter expanso, basi in canalem digitatam producto, 

 columella, et aperturm fauce iiderdum Icsvigatis, in- 

 terdum deme cormgatis. Operculum corneum, eras- 

 sum, oblougum, acuminatum. 

 Shell ovately oblong, ventricose, spire more or less acumi- 

 nated, last whorl much larger, with the lip largely 

 expanded into a clawed wing, base produced into a 

 clawed canal, columella and interior of the aperture 

 sometimes smooth, sometimes densely wrinkled. 

 Operculum horny, thick, oblong, acuminated. 

 The ten characteristic forms which have been associated 

 under the bead of Pterocera, are mainly distinguished by 

 the outer lip being widely expanded over the summit of 

 the spire, and developed into a number of spreading claws. 

 The sculpture and even the colouring of the whorls about 

 the spire is very simOar in all. The typical varieties of 

 character iu the different species reside in the clawed bp, 

 and in the columella and interior of the aperture, which 

 are often brilliantly coloured. In P. chiragra and rugosa 

 the bp is expanded into six widely spreading claws, the 

 columella and aperture being smooth in the first-named 

 species, and wrinkled in the second. In P. brijonia, 

 lambis, and aurantiaca, tliere are seven claws, and the 

 columella and aperture are smooth. In P. scorpius and 

 pseudo-SCO rpio, with seven claws, the columella and aper- 

 ture are densely wrinkled, and the claws are nodose. In 

 P. ehngata and millepeda with ten, and in P. multipes 

 with eleven claws, the columella and aperture of all three 

 are densely wrinkled. 



No representative of this genus has been found in any 

 part of the American coast. P. rugosa and hryonia were 

 collected by Mr. Cuming at the Society Islands ; the rest 

 are from the Eastern Seas. 



Species 1. (Mus. Cuming.) 



Pterocer.v BRYONi.i. Pter. testa ovato-oblongd, spirii, 

 nunc acuminata,, nunc truncata, arifraclibus subtiliter 

 striatis, superne concavis, ad angulum fortiter nodatis, 

 anfractu ultimo labro latissime expanso, heptadacti/lo, 

 columella callosd, IcBvi, apertura fauce Imvi ; albidd, 

 fuscescente vix tincta, columella et aperture fauci- al- 

 bido-carneis. 



The wild-vine root Pterocera. Shell ovately oblong, 

 spire sometimes acuminated, sometimes truncated, 

 whorls finely striated, concave round the upper part, 

 strongly noduled at the angle, last whorl with the 

 lip very widely expanded, seven-clawed, columella 

 callous, smooth, interior of the aperture smooth ; 

 whitish, but little stained with brown, columella aiul 

 interior of the aperture whitish flesh-colour. 



Slrombus radix hryonia, Chemnitz, Conch. Cab. vol. x. 

 p. 327. pi. 159. f. 1512-15. 

 Strombus bryonia, Gmelin. 

 Eadem var. Pterocera Seb/s, Valenciennes. 



Hab. Society Islands ; Cuming. 



The spire of this, the largest species of the genus, is 

 sometimes acuminated, sometimes flatly truncated. M. 

 Valenciennes and M. Kiener regard these varieties as 

 distinct species. 



