620 MESSES. GAEDNEE, KEEPIN^G, AND MONCKTON ON THE 



of undescribed species under each genus. !N"o doubt manj- of them 

 have been described on the continent ; but to examine each case 

 critically would be equivalent to monographing the entire series of 

 Barton MoUusca. We have contributed to the clearing up of the 

 synonymy by exchauging as many species as possible with M. Coss- 

 mann, who is now engaged in revising and supplementing Deshayes's 

 work on the MoUusca of the Paris Basin, and thus assuring ourselves 

 that the correct names are in use. II. Lefevre, of the Societe Mala- 

 cologique of Brussels, has also kindly certified a number of the species 

 for us, and we believe that the list, if not faultless, will yet be of 

 considerable use to collectors. 



We have met with no record of the discovery of any Mammalian 

 remains in the Bartons, though they are far from uncommon in the 

 Lower Headon of Hordwell, except that of Zeuglodon by a coast- 

 guardsman named Addow, on the shore, in stiff tenacious clay of the 

 Middle Barton. It was purchased by Dr. Wanklyn, and has not 

 been seen since his death some years ago. 



Pragmentary remains of Crocodiles and Chelonians are quite 

 abundant in the lowest beds of Highcliff, but have not been deter- 

 mined specifically. Eor the extensive list of fish-remains we are 

 mainly indebted to Mr. Davies, of the British Museum ; most of them 

 are the teeth and spines of Sharks and Bays, and the species, as a 

 rule, have a wide range. 



The Molluscous fauna is by far the most important, and may be 

 divided into three great groups. That comprising the largest num- 

 ber of species is peculiar to the Lower Bartons and occurs in the 

 small pockets of fine grey sand known as the Highcliff Sands. 

 Mingled with the fry of larger species is a great number of minute 

 but adult shells, some of which occur in such incredible profusion 

 that an ounce of the sand may contain hundreds of individuals of a 

 species, whilst others are so rare that only solitary examples are 

 known. The relative prevalence of the species varies in samples 

 from different pockets, but by far the most abundant, Corhula pisum 

 perhaps excepted, is il/{^raparz;a, the next heing 2Iargi7uUa hifido-pli- 

 cata. Next come Bulla elliptica,Bayania delibata, Yolvula lanceolata^ 

 Stromhus hartoneoisis, and then, but in rapidly decreasing numbers, 

 several other Bidlce, Volvaria acutiuscida , Sigaretus clatJiratus, Ac- 

 tceon Cossonanni, Bayania rudis, Eulima goniopliora, Marginella 

 pusilla, Teinostoma duhium, and Adeorbis elegcms*. Most of the 

 remaining minute forms may be considered rare, but the fact that 



* The number of shells I have extracted from a single pocket, some J peck of 

 sand, is as follows : — of Mitra parva 400, Bayania delibata 326, Marginella 

 bifido-plicata 120, Volvula lanceolata 14.0, Orthostoma crenatum 1S8, Natica Noes, 

 K lahellata, and N. perforata together 124, Buccinum Solandri 90, Strombus 

 bartooiensis 72, Bulla elUptica 70, Buccinum, sp., 58, Cerithiura filosum 60, 

 ActcBon Cossmanni 41, Bayania rudis and Eissoa bartonensis each 40, Bulla 

 comdus 37, Bulla pseudo-elliptica 20, Sigaretus clathratus 18, ActcBon simii- 

 latus 16, Volvula acuminata 14, B. angystoma 13, Etdima macrostoma 13, Num- 

 mulites elegans 12, Bingicula ringens 7, Eulima munda, E. goniophora. Bulla 

 anomala, B. Sowerbyi, and Acteson, sp., 4 each, Marginella pusilla and Nerita 

 inornata 3, Bulla ovulata 2, and the rest 1 each. Corals 35. 



