39 



Alopecias supkrciliosus. 



At once distinguished from the only other known species of the 

 genus, Carcharias vulpes, Cuv., by the enormous eye and its promi- 

 nent brow. I have at present only seen a single young example. 



A paper " On Parthenia, a new genus of Recent Marine Shells or 

 Mollusks, containing British Species," also by the Rev. R. T. Lowe, 

 M.A., was then read. 



Genus Parthenia. 



Testa eximie turrita, acuminata, imperforata, plerumque lactea, 

 epidermide pallida s. fere nulla; spira apertura longiore ; anfracti- 

 bus plurimis, costis striisque eleganter sculptis, ssepe cancellatis. 

 Apertura ecanaliculata, ovata, integra : columella simplex, antice 

 efFusa, postice aliquando torta s. plicata : labrum tenue, simplex. 



Obs. Testae figura et sculptura elegantissimse, parvulae. Animal 

 corpore admodum spirali ; pallio simplici, ecanaliculato ; pede antice 

 abrupte truncate, postice attenuate exappendiculato, operculifero. 

 Tentacula duo, triangularia s. prismatica, basi coalita, oculis sessi- 

 libus, superne ad basin internam positis, approximatis. Buccie la- 

 biales coalitse, infra tentacula exsertae, proboscidem abbreviatam, 

 depressam, profunde emarginatam s. bilobam referentes. Opercu- 

 lum aperturae fere magnitudine, comeum, tenue, ovatum, integrum ; 

 nucleo } 



Obs. Animal marinura, branchiis pectinatis, corpore caplteque 

 simplicibus, sc. nee velo nee membranis neque ciliis instructum. 

 Tentacula figura fere LimncEce ; sed elongatiora, e membrana longi- 

 tudiualiter ab apice ad medium basis conduplicata constare videntur. 

 Figura pedis inter Gasteropodes non siphoniferos infrequentior, in 

 Rissois tamen seque obtinet. 



Genus et animale et testa distinctissimum, cum Melaniis, Eulimis, 

 Turritellis, &c., a testaceologis recentioribus diutius confusum. 



The group proposed for generic distinction consists of several shells 

 remarkable for their elegance of form and sculpture, but which it 

 has been neither easy to associate with others in established genera, 

 nor advisable, in the absence of all knowledge of the animal, to place 

 apart. Accordingly, they have been variously arranged by different 

 authors. Philippi, in his excellent Enumeratio Molluscorum Sicilite 

 (Berol. 1836), whilst uniting some of them with several species of 

 EuUma, Sow., under the head Melania, Lam., has not failed to re- 

 mark their discrepancy as marine shells from the last-named genus, 

 and to point out the probability of their formation into a genus or 

 subgenus, " quando animalia eorum cognita erunt" : the species 

 which belong to Eulima, Sow., being, after Bronn, considered by 

 him to be congeneric with Niso of Risso. The genus Eulima, as 

 proposed by Risso, consisted of the same exceptionable kind cf mix- 

 ture ; but being now ably defined by Sowerby, and restricted within 

 its proper limits to the latter of these groups, the type of which is 

 the Turbo politus of some British authors, I am induced to brino- for- 

 ward, in relation to the other, some materials obtained twelve or 



