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52 



POLYGYRIDAEt 



i 



POLYGYRA PALL I ATA (Say) 



The species Polygyra paUiata is a rather large snail whose 

 shell, when mature, usually attains a diameter of nearly an inch 

 (21-22 mm.). The shell is of a uniform yellowish-brown colorJj 



and its surface is covered with* 

 short, stiff hairs. It has 5 whorls. 

 The spire of Polygyra palUata is 

 less elevated than is that of many 

 other species of Polygyra, and the 

 periphery, or outermost edge of 

 the shell circle, is marked by a 

 rather distinct ridge or carina. 

 The umbilicus is closed, and the peristome, which is widely 

 reflected, has a distinct labial denticle and a smaller, less distinct 

 peristomal denticle. A long, curved plait on the parietal wall 

 extends backward to the callus, closing the umbilical region. 

 The denticles in the aperture of Polygyra palliata are white. 



The animal (see page 40) is of a uniform slate color over 

 the upper surface and of a somewhat lighter color beneath. It 

 appears to be much too large for the shell. 



This snail, which is probably an emigrant from Indiana, 

 where it is common in places, is very rare in Illinois. At present 

 it has been reported from only White and Wabash counties, 

 where it has been found in forests of oak and hickory along the 

 floodplain of the Wabash River. 



Dr. Henry A. Pilsbry raises the question as to whether 

 Polygyra palliata is distinct from Polygyra obstricta. He writes, 

 "While P. palliata occupies an area generally north of that of 

 P. obstricta there is a broad belt of territory common to the two, 

 in some parts of which intergradation takes place, or, in other 

 words, remnants of a variable, undiliFerentiated, parent race still 

 exist." It would be of interest it similar series of shells could 

 be found in the overlapping area of distribution occupied by 

 these two species. 



Snails were used in love divinations; they were set to 

 crawl on the he.irth, and were thought to mark in the ashes 

 the initials ot the lover's name. On the subject ot these divi- 

 nations there is a most curious passage in the third Idyl ot 

 Theocritus. — W. Carew Hazlitt, Faiths and Folklore 



