106 MANUAL OF THE MOLLUSCA. 



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

 littoral, or even marine, in their habit. 



Low Coral Islands, 

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

 2 Fartulee 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, Tomatellina 1, Cydophorus 1, and Melanvpua 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 found Limnoea 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 Achatinellae are elongated {Leptachatina, G.) and the Helices 

 planorboid and multispiral. In Molokai the Achatinellse are 

 large and coloured. 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 3 



Nanina 6 Achatinella 204 Vitrina ,..„ ,. 2 



Bulimus.,, 5 Tomatellina 3 Succinea 10 



Partqla 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 ap. of Nanina, 1 Partula, and 1 Helicina, 



NEW WORLD. 



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/^fma vulgaris), one of the most abundant 

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



