106 MANUAL OF THE MOLLUSCA. 



[Taheitana) Neritina, and. Navicella ; the two last being often 

 littoral, or even marine, in their habit. 



Loiu Coral Islands. 



The Atolls, or lagoon-islands, are less prolific : 2 Helices and 

 2 FartulcB are found at Oualan, in the Caroline Archipelago ; 

 and from Chain Island {Annaa), the centre of commerce in the 

 eastern Archipelago, have been obtained — Helix 2 sp., Nanina 1, 

 Partula 1, TornatelUna 1, Cydophorus 1, and Melanipus mucro- 

 natus. 



Sandwich Islands. 



The land shells of these islands exceed 200, and are all, or 

 nearly all, peculiar : there is one Limax ; and in the fresh waters 

 are fdund Linwujea volutatrix, Physa reticulata (Gould), Neritopsis ? 

 Neritina Nuttalli and undata, and Unio contradens (Lea). 



In the I. Kaui, two species of Achatina have been found : 

 the Achatinellse are elongated {Leptachatina, G.) and the Helices 

 planorboid and multispiral. In Molokai the Achatinellce are 

 large and coloui-ed. In Maui and Oahu the Helices are small 

 and glabrous, or hispid, ribbed, and toothed. In Hawaii, Suc- 

 cineas prevail, and Achatinellae are rare. (Gould.) The large 

 number of Achatinellae is partly due to this group having been 

 specially studied by Judge Cooper of America. 



Helix 20 Achatina 5 Pupa 2 



Nanina 5 Achatinella 204 Vitrina 2 



Bulimus 5 Tornatellina 3 Succinea 10 



Partula 4 Balea 1 Helicina 6 



The Island of Guam, Ladrones, has 3 sp. of Partula, 2 of 

 Achatinella, and 1 Omphalotropis. At the Marquesas have been 

 found 3 sp. of Nanina, 1 Partula, and 1 Helicina. 



NEW WOELD. 



16. Canadian Eegion. 



The country drained by the Great Lakes and the river St. 

 Lawrence possesses very few peculiar shells, and these mostly 

 of fresh- water genera. It is chiefly remarkable for the presence 

 of a few European species, which strengthen the evidence before 

 alluded to (p. 60) of a land-way across the north Atlantic 

 having remained till after the epoch of the existing animals and 

 plants.* 



* For example, the common Heather ( Ca/ZM?ia vulgaris), one of the most abundant 

 social plants of Europe, characteristic of the moorland zone, and seldom rising above 



