1906.) NATURAL SCIENCES OF PHILADELPHIA. 537 



pies the northern central portions of the area, while the less evolved 

 typical form is peripheral. There is, however, no line to be drawn 

 between them, as in many places both forms and the intergrades 

 occur together, and in the Choctaw Nation especially, most specimens 

 are intermediate in size of the umbilicus. 



In 1903 we took the species at eleven localities in Missouri, Arkansas 

 and Indian Territory. Some of the specimens from the bluff along 

 Grand River at Wyandotte, near the northeast angle of Indian Terri- 

 tory, are the largest I have seen, and also the most extreme of the 

 sampsoni form, diameter 8 to 9.3 mm. (PI. XX, figs. 17, 18, 19). Those 

 from Limestone Gap, Indian Territory, and Magazine ]\It., Ark., are 

 intermediate in characters. At Mammoth Spring, Fulton Co., north- 

 east Arkansas, only typical dorfeuilliana was taken, the shells being 

 small, 6.7 mm. diam. (PI. XX, fig. 12). This is exactly the size given 

 by Lea for the type, .3 inch. 



In originally describing this species. Dr. Lea gave the locality as 

 "Ohio, Mr. Dorfeuille, Cincinnati," Mr. W. G. Binney states that 

 ■' ' Mr. J. G. Anthony obtained from ]\Ir. Dorfeuille some facts concern- 

 ing the original discovery of this species, which prove beyond all doubt 

 that it was accidentally brought from Kentucky." It is on the 

 strength of this that he reports it from "Kentucky, opposite Cin- 

 cinnati." Binney also records dorfeuilliana from "Coosa River, Ala- 

 bama. ' ' 



A somewhat extensive correspondence with active collectors has 

 failed to bring out any definite locality for dorfeuilliana in Kentucky, 

 Tennessee or Alabama. Inquiry among Cincinnati conchologists has 

 elicited no further confirmation of Mr. Dorfeuille's Kentucky record. 

 Mr. Bryant Walker wTites: "There are no P. dorfeuilliana from east of 

 the Mississippi, so far as I can find, in the Wetherby collection. I 

 have two specimens labelled 'Ky.' sent me years ago by Anthony, 

 •and one from the Lathrop collection from ' Wn. Tennessee.' " 



Dr. W. H. Dall, of the U. S. National Museum, under date of October 

 21, 1905, writes: "I have looked over our series of dorfeuilliana Lea. 

 One, marked by Lea 'type,^ has the locality 'Cincinnati,' but the 

 label records no collector's name, but the original description credits 

 it to Dorfeuille. There is also a fragment from Florida named by 

 Binney dorfeuilliana, but which in my opinion is a fragment of avara. 

 The first is No. 116,779, the other 47,318. We do not have it from 

 Alabama. All our series are from Indian Territory, Arkansas, Louisi- 

 ■ana, Texas. I feel quite confident the Ohio or Kentucky locality is 

 ■erroneous." 



