LUSITANIAN REGION: 95 
4 Oyclostomide. Of these, 60 are peculiar, 12 are common to 
Southern Europe, and 4 to the West Indies? 1 to Morocco, 1 to 
Algeria (also European), and 1 to Egypt. The fresh-water 
shells are Physa 2, Ancylus 1. 
Heliz ustulata and McAndret are peculiar to the rocky islets 
known as the ‘‘ Salvages,” north of the Canaries. 
The absence of Western African land-shells, and the presence 
of West Indian species may be explained by the currents which 
come from the Antilles, as shown on the map.* Some of the 
European species may have been introduced (e.g., Helix lactea, 
pisana, cellaria); but the presence of 20 Lusitanian species, in a 
total of 80, is too remarkable to be accidental. 
The Cape de Verde Islands, although much farther to the south, 
are also much farther from the continent, being 320 miles west 
of Cape de Verde; the mean temperature is 65°—70°, and the 
vegetation, as Dr. Christian Smith remarked, is more like that 
of the Mediterranean coast than West Africa. Of the 12 land- 
shells, two are common to the Canaries and Azores, 
Lusitanian Species of Wide Distribution. 
Helix amanda, Sicily—Palma. 
3, planata, Morocco—Canaries, 
,, lenticula, S. Europe—Mudeira—Canaries. 
»  rozeti, Sicily, Morea—Algeria—C. de Verde—Canarles 
3, lanuginosa, Majorca—Algeria—Palma. 
» simulata, Syria—Egypt—Lancerotte. 
» Michaudi, summit of Porto Santo—Teneriffe ? 
» eyclodon, Azores—Canaries—C. de Verdes. 
» advena, (= erubescens Lowe), Madeira—Azores—St. Vincent. 
pliearia and planorbella, Canarles—Porto Rico? 
Baling subdiaphanus, Canaries—Azores—C. de Verdes. 
»  beeticatus and badiosus, Canaries—St. Thomas ? 
Ascension.—This barren yolcanic island, in the midst of the 
Atlantic Ocean, is not known to possess any terrestrial Pulmoni- 
fera beside a slug, the Limawz Ascensionis. Mr. Benson thinks 
that some J/elicidee might possibly be found on the Green 
Mountain, 2,840 feet high, where the garrison have their gar- 
dens. Mr. Darwin remarks ‘‘ we may feel sure that at some 
former epoch, the climate and productions of Ascension were 
yery different from what they now are.” 
St. Helena (No. 28 of Map). 
The island of St. Helena is 800 miles S.E. of Ascension, and 
1200 from the nearest African coast of Benguela. It is entirely 
* Long before the discovery of America it was observed that the westerly gales 
washed ashore stems of bamboos, trunks of pines, and even living men in canoeés.— 
Humboldt, ii. p, 462. 
