CANADIAN REGION. 399 



Helix hortensis (imported) coast of New England and banks of St. Lawrence. 



„ pulchella (smooth var. only) Boston, Ohio, Missouri. 

 Hel'icella cellaria (giapliyra. Say ?) N. E. and midcUe States. 



„ pura, nitida and fulva ? 



Zua lubrica, North West Territory. 

 Succinea amphibia ( = campestris, Say ?) 

 Limax agrestis (= lunicatus, G.) Mass. 



,, flavus, New York, introduced. 

 Vitrina pellucida (= Americana ?) Limnaea palustris ( = elodes, Say ?) 

 Arion hortensis, New York (Dekay.) „ truncatula ( = desidiosa ?) 

 Aplexa hypnorum ( = elongata. Say ?) 

 Auricula deticulata, Mont., New York Harbour.* 

 Alasmodon margaritiferus (= arcuatus, Barnes.) 

 Anodon cygneus {= fluviatilis, Lea ?) 



The shells proper to Cauada, or derived from the adjoining States, are 

 only G sp. of Helix, 2 Succineas, and 1 Pupa ; 8 sp. of C^clas have been 

 obtained from the region of Lake Superior. 



The following species occur in New England : — 



Helix 13 Physa '2 Unio 5 



Succinea 2 Planorbis 11 Alasmodon 2 



Pupa 7 Paludina 1 Anodon 2 



Limnsea 7 Valvata 2 Cyclas G 



Ancyius 2 Auricula 1 Pisidium 1 



Cari/chium exiguum. Say, is found in Vermont, and Limnaa (Acella) 

 ym6*?725inLakeChamplain; Valvata iricannafaand Paludina decisanxt cha- 

 racteristic forms. 



The genera Clausilia and Cyclostoma are entirely wanting in Cauada and 

 the Northern states. The Limacidce are represented by PJiilomi/CHS, of 

 which there are 9 reputed species, ranging from Mass. to Kentucky and 

 South Carolina. 



17. Atlantic States. 



The parallel of 36° N. Lat. forms the boundary-line of two botanical 

 regions in the U. States, but the evidence of the fresh-water shells, in 

 which they are particularly rich, seems to favour a division into two 

 hydrographical provinces, — the region of the Atlantic streams and the basin of 

 the Mississippi. Above 50 fresh-water Fulmonifera, V^^ i^ectinibrancldata, and 

 250 bivalves are reputed to be found in the States, and it is supposed that only 

 a few species are common to both sides of the AUeghanies. Cyclas mirahilis, 

 Pisidium Virginicum, Cyrena Carolinensis, and Unio co7nj[)lauatMS and radiatus 

 are characteristic of the eastern rivers ; Melania depygis is said to be tlie 

 only member of that large genus found eastward of the Hudson River. Of 

 the American land-snails, 29 sp. of Helix, 6 Succineas, and 13 Pupas are 

 enumerated from the Atlantic States. In Florida the propinquity of the West 

 Indian Fauna is strongly indicated by the occurrence of the great Glandina 

 tnmcata, by species of Cylindrella, and a Helicina. A Cuban species of 



