38 TERIiESTKIAL AIR-BREATHING MOLLUSKS. 



BuIimuluB patriarcha. Stenogyra octonoides. 



alternatus. Pupa pellucida. 



Schiedeanus. Buccinea Haleana. 

 Macroceramua Gossei. concordialis. 



Holospira Goldfussi. luteola. 



Roenieri. Salleana. 



Of the above Polygyra JacJisoni and Zonites siynijicans are included 

 with great hesitation. They are found at Fort Gibson, in Indian Terri- 

 tory.^ They are more reUited to the fauna of the Cumberland Sub- 

 Region than that of Texas. 



Besides the species characteristic of the North American fauna which 

 Texas has as a portion of the Southern Region of the great Eastern 

 Province, we find in the above list two species peculiar to it of the char- 

 acteristic American subgenus Mesodon, — Roemeri and divesta} 



Several species on the list have been introduced from other regions,' 

 such as Strohila Hahhardi,'^ a Jamaica species, as well as Maa'oceramus 

 Gossei, a Cuban species, which is also found on the Florida Keys. Micro- 

 physa incrustata from Cuba, as well as Pupa pellucida and Stenogyra 

 octonoides. 



Of the remaining species on the list, sixteen have actually been found 

 in Mexico ; probably all will be, as there seems no well-defined boun- 

 dary here between the North American and Mexican fiiuna. 



Bulimulus serperastrus, Say, although actually found in Texas, is evi- 

 dently a member of the Mexican fauna, and is therefore omitted from 

 my list, though included in the descriptive portion of my work. 



The characteristic of Texas appears to be the great preponderance of 

 the genus Polygyra, of the type of P. I'exasiana, while the type of Flor- 

 ida, the septemvolva, is almost wanting. The great abundance of indi- 

 viduals is also remarkable, showing the Region to be peculiarly adapted 



1 See Vol, I, 122, which gives the limits of the corresponding "Southern Interior Sec- 

 tion " such as would include these species. Several of the species of East Tennessee, also, 

 have been found in Arkansas, — a fact also favoring a wider limit to the Cumberland Sub- 

 Region. 



8 This species has not actually been found within the limits of the State of Texas, but 

 in the neighboring State of Arkansas and in Mississippi. To it may be applied the re- 

 marks on Zonites significans and Polygyra Jacksoni above. 



* Either by commerce, by oceanic currents, or from some former molluscous fauna of 

 which these now isolated localities were offshoots. 



* Since the above was written, this species has been found by Dr. Newcomb near Sa- 

 vannah, Georgia. It may therefore prove a widely distributed American species. In 

 Jamaica it is known as H. Vendreysiana, Gloyne. 



