254 Mr. L. Reeve on the Geographical Distribution of the Bulimi. 



sure by a group of large Achatina, which inhabit principally the 

 hot and swampy districts on the banks of the Gambia, Nun, 

 Gaboon and Niger rivers, and i-each in a modified fonn to the 

 sandy plains of Loanda. The shells are large, inflated, and richly 

 dark-painted, and the shells of the few Bulimi that are associated 

 with them belong to the same characteristic type. The two ge- 

 nera meet at this point. Bulimus torridus of Liberia and Acha- 

 tina Saulcydi belong to the same natural type, notwithstanding 

 that they are referred to different genera. B. Adansoni, Afri- 

 camiSy tenebricus, turbinatus, flammeus, Numidicus, and inter- 

 stinctus, belong also to the Achatina type. B. neuricus, Gui- 

 neensis, and vivipara are thi'ee fragile species of different habits 

 from the same country, and another type is presented in B. 

 tumefadus and pemphigodes with peculiarly globose inflated 

 shells. As an instance of the mingling of types on the confines 

 of the great provinces of distribution which meet in North 

 Africa, it may be remarked that B. Ruppellianus inhabiting the 

 eastern confines belongs to this Achatina type, and B. reticulatus 

 inhabiting the western belongs to the Syrian Bulimus type, which 

 is exactly the reverse of the general typical character of the Bulimi 

 in these localities. B. Doivnsii, found abundantly at Princes 

 Island off the coast of Guinea, inhabits also the nearest main 

 land. At St. Helena a small brown species is found, B. He- 

 lena; and in the more elevated parts of the island, in an appa- 

 rently semifossil state, the remains of an extinct type, B. auris- 

 vulpincB, are found. Mr. Darwin, who observed this well-known 

 species at St. Helena imbedded in the soil, attributes the extinc- 

 tion of it to some recent geological disturbances, which caused 

 the entire destruction of the woods and consequent loss of food 

 and shelter to the snails. 



Nothing is known of the Bulimi of Africa, south of the tropics, 

 excepting those described by Dr. Krauss from the neighbourhood 

 of Natal. Eight species collected in this part are of very miscel- 

 laneous character, but typically distinct from those of the west 

 coast. B. Natalensis, comdus, and spadiceus are thin and glo- 

 bosely convoluted, B. Burchellii and meridionalis are of light 

 ovate form, and B. linearis and turrceformis are elongated. They 

 are all small. A very remarkable species has, however, been dis- 

 covered in this locality, B. Kraussii, nearly equal in size to the 

 largest Bulimus of tropical America and as brilliant in colour. 

 From Mozambique we have but one small light species, B. Mozam- 

 bicensis. In Madagascar are two species of large size and elon- 

 gated form, B. clavator and obtusatus, differing essentially from 

 any of the continental types ; and in the Seychelle Islands are 

 two, B.fulvicans and velutinus, partaking in some measure of the 

 smaller Natal species. In Mauritius there is only one small 

 ground species, B. clavulinus. 



