Zoological Society. 387 



Halmatubus Binoe . Halm, corpore pallide fuscescenti-flavo, suprcL 

 nigro penicillato, subtus dilutiore ; caudd ad apicem fuscescenti- 

 nigra ; aiwibus externe ad apicem, margineque antice, nigris. 



line. lin. 

 Longitudo ab apice rostri ad caudse basin. ... 21 



ad basin auris .... 4 6 



cuudic 20 



tarsi digitorumque 7 9 



auribus 2 3 



Hab. Port Essington. 



The following paper, by Mr. Lovell Reeve, entitled " Monograph 

 of the genus Tornatella, a small group of Pectinibranchiate Mollusks 

 of the family Plicacea, including descriptions of seven new S2)ecies, 

 from the collection of H. Cuming, Esq.," was then read. 



ToRXATELLA, Lamarck. 

 Testa ovalis, cylindracea, plerumque transversim striata, raro Isevis- 

 sima, spira brevi, apice acuto ; apertura longitudinali, superne 

 angustata, inferne Integra, rotundata ; columella incrassata, vald6 

 plicata ; labro simplici, solido, acuto. Molluscum marinum, pecti- 

 nibranchiatum, operculo corneo, minuto, instructum. 

 The very wide range of characters which were selected by Linnaeus 

 for the determination of genera induced many inaccuracies in his 

 method of classification which might certainly have been avoided, if, 

 instead of generalizing upon the external variations of the shell, he 

 had pursued a more searching inquiry, like his contemporaries 

 Adanson and Forskael, into the nature of its animal inhabitant. 

 His genus Valuta, for example, founded upon the character of the 

 columella being obliquely plaited, included both phytophagous and 

 zoophagous mollusks, animals both with and without proboscis, and 

 respiratory siphon. The presence or absence of these organs, distin- 

 guishing the plant- eating from the flesh-eating mollusks, is however 

 still indicated to a certain extent in the shell, by the basal forma- 

 tion of the aperture ; and Bruguiere, the conchologist of the ' Ency- 

 clopedic Methodique,' appears to have sagaciously detected the 

 difference between the shells of the true Valuta and those which 

 were subsequently selected by Lamarck for the formation of this 

 genus ; the base of the aperture being sinuated or canaliculated in 

 the one, and entire in the other. But the alteration proposed by 

 Bruguiere was little or no improvement upon the arrangement of 

 Linnaeus ; for in removing the TornatellcE to his genus Bullmus, they 

 became associated with a miscellaneous assemblage of mollusks, dif- 

 fering most essentially both in their organization and habits. They 

 were then distinguished by Lamarck by the above generic title ; 

 whilst De Blainville included them, together with some w/r- breathing 

 mollusks, in a new genus under the name of Pedipes. The arrange- 

 ment followed by the learned author of the ' Manuel de Malacologie* 

 was thus scarcely better than that of his predecessor Bruguiere ; he, 

 however, cautiously abandoned it, when the propriety of Lamarck's 

 distribution of the Tornatellce was subsequently confirmed by Gray 

 in the discovery of their being operculated. 



