193 



He showed that the cancelli in all those bones that assist in 

 sustaining the weight of the body, or in locomotion, are arranged 

 in definite directions, the directions being those of the reception 

 and transmission of force. The neck of the thigh bone was par- 

 ticularly described, and shown to consist within of cancelli so 

 arranged as to form a framed arch or truss. This structure of the 

 neck of the thigh bone he had not detected in any other animal, 

 except a very slight manifestation of it in the Chimpanzee (Trog- 

 lodytes niger) and the Engeena, (T. gorilla) which are the most 

 anthropoid species of the brute creation. 



Dr. Gould exhibited to the Society a number of new 

 species of shells from Africa, recently presented by Dr. 

 Perkins. 



Vaginulxjs Liberianus. v. corpore ovali, elongate, postice 

 ampliato, fuscato infra pallidiori, maculis inequalibus laceratis 

 nigris utroque asperso et linea dorsali mediano pallido notato ; 

 solea trientem latitudinis adequante, transverse rugosa ; tentacu- 

 lis parvis oculiferis bulbosis. Long. 2. lat. ^ poll. Hob. Li- 

 beria. 



A smaller and more slender animal than V. Floridanus. Its 

 blotches are also larger and less numerous, and occur underneath 

 as well as on the back. In form it compares somewhat with V. 

 Langsdorfiii from Brazil, but not in coloring. 



SucciNEA SPURCA. T. parva, fragili, virescente, striis laxis, 

 scabris, lutum cumulantibus ; spirse anfr. 3 ventricosis ; sutura 

 profunda; apertura rotundato-ovata, trientes duos longitud. testae 

 adequante ; columella acuta, valde arcuata, absque plica. 

 Long, y^^, lat. y% poll. Hah. Liberia, on the moist sides of 

 water-pits, and in crevices of trees. 



Similar to »S. avara in form and in the peculiarity of becoming 

 invested with an earthy coating. It differs in its paler color, and 

 its more arched columella. 



SucciNEA HELicoiDEA. T. parva, late umbilicata, tenui, stra- 

 minea, supra oblique lirata, infra laevigata ; spira depressa, anfr. 

 3J rotundatis, ultimo subangulato ; apertura lunata, alia. Diam. 

 I ; alt. i poll. 



A singular shell, whose form and texture would lead us to 



PROCEEDINGS B. S. N. H. 13 APRIL ^1850. 



