INVERTEBRATE ANIMALS. 39 



Limpet tribe, but the animals are widely 

 distinct. 72 species are exhibited, most of 

 them presented by Mr. F. P. Marrat. 



Upper Compartment. 



Drawings of the animals of Siphonaria and Patella. 



Group 111.— Sub-order LIMNOPHILA. A/|av>j, a pool; 

 (^i'aoj, a friend. Estimated number of species : recent, 

 700 ; British, 25 ; fossil, 160. Tertiary. 



51 Examples of Auricula, Scarahus, Limnea, Plan- 

 orhls, Physa, Physopsis, &c. A brackish or 

 fresh-water group, as indicated by the pale or 

 sombre colouring even of the tropical species. 



Group 112. — Sub-order GEOPHILA. yij, the earth ; t^lxos, 

 a friend. 



Family LIMACID^ and allies. Imax, a slug. 

 Estimated number of species : recent, 200 ; British, 13. 

 Examples of Limax, Avion, Nanina, Helicarion, 

 &c. The beautifully coloured shells of Nanina 

 appear to advantage in a group where most of 

 the species are without shells. 



Upper Compartment, 



Drawings of the Animals. 



Family HELICIDiE. £A»xr], a winding. 



Group 113.— Sub-family HELICINiE. Part I. The influ- 

 ence of geographical position is well illustrated in this 

 group, by the family likeness subsisting between the 

 members of the smaller series, Brazilian, N. American, 

 Madeiran, and European. Estimated number of species : 

 recent, 408 ; British, 10 ; fossil, a few. Tertiary. 



