NOTES OX THE FKESH-WATER MOLLUSK PLANORBIS 

 MAGXIFICUS AND DESCRIPTTOXS OF TWO XEAV 

 FOE:\rS OF TTTE SAME OEXTTS FROM THE SOUTH- 

 ERN STATES. 



Py Pax: I. Bartscit, 



AssMdiit Cnnitor. Diiision of Mnllusls. J'. N. N<iti(ni<il Museum. 



Early in November. IDOC), tlie writer iinule a trip to Wilminoton, 

 North Oarolina, \n quest of that mao-nificent member of the genus 

 Planorhis^ Planorhis {Pierosoma) magnifrvs; which was described 

 by Dr. H. A. Pilsbry in the Nautihis." 



The h)cality cited was lower Cape Fear River. An examination 

 of the type lot at tlie Philadelphia Academy of Sciences created some 

 donbt in my mind about this l)eina- a liuviatile species. The thin 

 texture of the large shell appeared to me as indicating evidence of 

 a lacustrine form. 



Inquiry as to the larger lakes alxnit Wilmington resulted in the 

 location of Greenfield Pond, about a mile and a half south of the city. 

 This pond is formed by a broad earthen milldam, about 20 feet high, 

 which banks up the water between sand dunes, inundating the low- 

 lying ground, and transforming it into a lake, the digitations of 

 which, extend back for some '^ miles. Its greatest width probably 

 does not exceed 400 feet. A large portion is fringed with cypress 

 trees, and there are several cy])ress-covered islands in it. Tlie trees 

 are not large, hardly more than a foot in diameter, and are all draped 

 with large festoons of Spanish moss. The water of the lake comes 

 from springs, is unpolluted, and contains an interesting fauna and 

 flora. Conspicuous among the plants were long strings of Potamoge- 

 ton and several species of pond lilies, the leaves of which extend over 

 the surface of the w^ater. After a half hour's sifting of bottom mate- 

 rial and vegetation, I succeeded in finding many small mollusks and 

 the first fragment of the desired Planorhis. The sieve was discarded 

 for a time and a s^^stematic search among the heavier aquatic vegeta- 

 tion begun, which resulted shortly in discovering the fii'st perfect 

 living magnificus. The search continued all day, when, gathering 



'' Novembei-. 1003, X^'II, p. 75. 



Proceedings U. S. National Museum, Vol. XXXlll— No. 1587. 



697 



