268 DR. L. PFEIFFER ON NEW LAND SHELLS. [NoV. 25, 



The Eeavei'j the subject of the foregohig remarks, was presented 

 to the Society by the Hudson's Bay Company, in the autumn of 

 1861, and was probably then about six months old. It is, no doubt, 

 less vigorous than the large wild animals of this species, who would, 

 in all probability, bring down trees of much larger dimensions in a 

 shorter time. In fact, it was evident that our Beaver was a novice 

 in the undertaking, as he more than once slipped and rolled over on 

 his back in his eagerness to accomplish the task. It was impossible to 

 witness the actions of this animal without being struck by the amount 

 of skill and intelligence exhibited. When the space cut through 

 towards the centre was too narrow to admit its head, its teeth were 

 applied above and below so as to increase the width from the outside 

 towards the centre, until the remaining parts above and below formed 

 two cones, the apices of which joined in the middle. Again and again 

 the animal left off gnawing, and, standing upright on its hind legs, 

 rested its front feet on the upper part of the tree, as if to feel whether 

 it was on the move. This showed clearly that the creature knew 

 exactly what it was about. 



. Descriptions of Thirty-six New Land Shells, from the 

 Collection of H. Cuming, Esq. By Dr. L. Pfeiffer. 



(Plate XXXVI.) 



1. Helix dan^, Pfr. (172 5). T. angustissime umbilicata, sub- 

 turbinata, solida, superne cotifertim arcuata, 'plicatula, striis 

 spiralibus obsolete decussatula, cinnamomea ; sinra convecciiis- 

 culo-turbinata, vertice mimcto ; anfr. 6^, convexiuscidi, regula- 

 riter accrescentes, ultimiis nan descendens, medio subcarinatus, 

 bast subtiliter striatus, pallidus ; apertura obliqua, lunaris, 

 intiis submargaritacea ; perist. simplex, rectum, margine coin- 

 mellari sid/arcuato-declivi, sensim ad insertionem subdilatato. 



Diara. maj. 32, min. 29, alt. 19 mill. 

 Hab. Lao Mountains, Camboja (Afoi«/io^). 



2. Helix mitis, Pfr. (447 a). T. umbilicata, convexo-dept'essa, 

 tenuiuscula, Icevigata, diaphana, alabastrina ; spira parum ele- 

 vata, conoideo-convexa ; sutura submarginata ; anfr. 5, con- 

 vexiusculi, sensim accrescentes, idtimus subdepresso-rotundatus ; 

 umbilicus angustissimus, vix pervius ; apertura parum obliqua, 

 lunai'is, intus nitida ; perist. simplex, rectum, marginibus vix 

 convergentibus, columellari arcuato, superne subdilatato. 



Diam. maj. 16-|, min. 15^, alt. 8| mill. 

 Hab. Lao Mountains, Camboja {Mouhot). 



3. Helix pluto, Pfr. (595 b). T. umbilicata, depressa, soli- 

 dula, superne striis spiralibus et aliis antrorsum descendentibus 

 minute sculpta, nitidula, fusco-nigricans, fasciis nonmdlis pal- 

 lidioribiis notata ; spira brevitcr conoideo-elevata, vertice ob- 

 tusulo ; anfr. 5 J, convexiiisculi, idtimus magnus, supra medium 



