INSECTS. 353 



extensively distributed over other countries. The Bulla 

 ttriata is found in Egypt and Senegal, along the coasts of 

 France and England, in the Antilles, and South America. 

 The Turbo petrczus, well known in Europe, is equally fami- 

 liar to the sun-burnt collector at the Cape. The Helix as- 

 persa^ so abundant in all the temperate countries of Europe, 

 has also been found in Africa, and as far west as the Canary 

 Islands. Another species, the Helix candidissima, frequent 

 in France and Spain, has been found in Tripoli and other 

 parts of the African continent. The Helix agira of Egypt 

 and Barbary is found in Provence, though not in Italy ; 

 while the Helix lactea of Spain and Algiers is unknown in 

 Provence, yet extends northward as far as Rousillon. 



Of other African shells we shall mention merely the 

 Cassis Madagascaricnsis, Patella granatina and testudinariay 

 Conus ammiralis, — a species highly prized by collectors, 

 Valuta armaia, Haliotis striata, and Oliva erythrostoma. 



The fossil shells of an extremely limited portion of Africa 

 are partially exhibited in the great French work on Egypt ; and 

 those of Mount Barkal have been illustrated by M. Cailliaud. 



Our knowledge of the geographical distribution of Insects, 

 notwithstanding the more careful study of the subject which 

 has prevailed of late years, may be said to be still in its 

 infancy. Latreille's little work, however imperfect, is the 

 most complete with which we have as yet been furnished.* 



It is easy to suppose that if certain plants are peculiar to 

 certain climates, so also insects, the greater proportion of 

 which not only feed on plants, but are each according to 

 its kind almost restricted to particular species, must in 

 like manner be characteristic of special localities. The en- 

 tomological characters of the southern shores of Europe 

 strongly exhibit their geographical approach to the African 

 continent. The Ateuchus sacer, various species of Scaunts 

 and Akis, the European scorpion, several CigalcB, Termites^ 

 and others, may be regarded, in the southern countries of 

 Europe, as the avarU-courriers of those more exclusively 



• "Introduction 4 la Geographic G^n^rale des Arachnides et des In- 

 sectes, ou des Climats propres A ces Animaux." Tliis memoir was read 

 to the Academy of Sciences in 1815, and forms part of the third volume 

 of the Memoires du Museum d'llistoire Naturelle." It was republished 

 in a separate volume by the same author, entitled " Memoires sur divert 

 Sujets de rHifitoire Naturelle des Insectes," &c. Paris, 1810. 

 Gg2 



