234 Geolugical Society : — 



of the Triloph. angustidens from Siraorre, Das, &c., and from the 

 Tetral. longirostris of Ei)])elsheim. I'he M. arvernensis of Mont- 

 pellier, Auvergne, Italy. &c. had no lower tusk?; and the author is of 

 opinion that the only specimen which has been figured and described 

 as one of the lower tusks of the Crag Mastodon is a terminal fragment 

 of one of the upper tusks of that species. 



From osteological considerations it appears that Tetral. arver- 

 nensis was of a low and heavy make ; that Tetral. longirostris was 

 of similar general proportions ; and that Triloph. angustidens was 

 higher in its limbs and of a comparatively light and slender shape. 



In his observations on the geological age and associated faunas 

 of the formations in which these species severally occur. Dr. Falconer 

 observed that Trilophodon angustidens is a characteristic species of 

 the miocene Falunian beds throughout Europe, and is associated with 

 Triloph. tapiroides in the Faluns of France and the upper freshwater 

 Molasse of bwitzerlaad. Tetraluphodon longirostris is an important 

 member of the Eppelsheim fauna, which, though its determination 

 is accompanied with great difficulty, appears to be identical in its 

 leading features with that of the Falunian deposits of France and 

 Switzerland. The Telrulophodon arvernensis is characteristic of the 

 pliocene fauna ; and it had a very extended range of habitat over 

 Europe, accompanying Loxodon meridionalis (Xesti) in Tuscany, — 

 Trilophodon Borsoni, Loxodon prlscus, and Euelephas antiquus in Pied- 

 mont and Lombardy, — Loxodon meridionalis at Montpellier, — and 

 Tril. Borsoni, Lox. meridionalis, and Lox. prisons, in \'elay and 

 Auvergne. After having reviewed the circumstances under which 

 Mastodon-remains occur in the British strata, Dr. Falconer con- 

 cludes that, — 1st. The Mastodon-remains which have been met with 

 in the Fluvio-marine and Red Crags belong to a pliocene form, namely 

 Tetralophodon arvernensis. 2ndly. 1 he Mammalian fauna of the Red 

 and Fluvio-marine Crags, regarded as a whole, bears all the cha- 

 racters of a Pliocene age, and is identical with the Subapennine 

 Pliocene fauna of Italy. 3rdly. The Red and Fluvio-marine Crags, 

 tested by their mammalian fauna, must be considered as beds of the 

 same geological age. 



Throughout this paper, for the sake of clearness, the subgeneric 

 names have been used in designating the species. The author, 

 finding that the name Elasmodon, ajiplied to the third group of 

 Elephants, in the ' Fauna Antiqua Sivalensis,' in 1847, had been 

 previously used for a fossil fish, has abandoned it, and api>lies the 

 term Euelephas in lieu of it, 



April 22, 1857. — Colonel Portlock, R.E., President, in the Chair. 



The following communications were read : — 



1. "Description of a Crustacean from the Lias Bone-bed." By 

 C. Gould, Esq., B.A. Communicated by J. W. Salter, Esq., F.G.S. 



I'he specimen described was found in a coprolitic mass from the 

 bone-bed of Aust Passage, by E. Higgins, Esq. It consists of a 

 carapace and four abdominal segments. The former is smooth, sub- 

 rectangular, with the eyes widely separated, and has three longitu- 



