MUSEUM OF COMPARATIVE ZOOLOGY. 213 



Equally wide over the Region has been the distribution of those 

 minute species whose origin has been traced to circumpolar regions 

 (see p. 205). Such are : Zonites viridulus, /ulcus, and Helix pul- 

 chella. 



In addition to these species derived from the north, are found the 

 following species peculiar to the Region, whose origin can be traced to 

 the south, in* the peninsula of Florida, from whence, indeed, many of 

 them have not yet spread over the whole Region : — 



Glandina truncata. Helix Hopetonensis. 

 Zonites cerinoideus. major. 



Helix auric ulata. jejuna. 



uvulifera. Bulimulus Floridanus. 



Postelliana. Dormani. 



espiloca. dealbatus. 



avara. Cylindrella jejuna. 



cereolus. Pupa variolosa. 



septemvolva. modica. 



Carpenteriana. Succinea effusa. 



Febigeri. campestris. 



pustula. Wilsoni. 



pustuloides. Veronicella Floridana. 



Of the more widely spread species, Helix septc7nvolva is represented 

 by various forms over the whole southern littoral region, both of the At- 

 lantic and Gulf. So is Glandina truncata, Helix jejuna, pustula, pustu- 

 loides, and Pupa modica. Helix Hopetonensis and major extend only 

 along the Atlantic alluvial Region. Bulimulus dealbatus is also dis- 

 tributed over the whole Region, from North Carolina to Texas, and has 

 spread northward to Arkansas and Kentucky. Succinea camjiestris ex- 

 tends along the Atlantic coast as far as South Carolina, as does also 

 Zonites cerinoideus, even into Nortli Carolina. Helix espiloca and Pos- 

 telliana have been noticed thus far in the southeastern corner of Georgia. 

 The former also at New Orleans and Indianola. Succinea Wilsoni, 

 at Darien, Ga. 



The following European species have been introduced by commerce 

 into this Region, and still exist at the points named : Slenogyra decollata, 

 Lin., and Helix aspersa, Miill., at Charleston, S. C. ; Acicula acicida, 

 Mull , Florida. 



From the list of species peculiar to the Southern Region it will be 



