210 THE CHICAGO ACADEMY OF SCIENCES. 



Habitat: The specimens in this region have been found 

 in rather low, damp or marshy ground. 



Remarks: This species is at once known by its semi-glo- 

 bose form and its two brown bands. It is a rare shell in this 

 area and the writer has been unable to obtain living specimens 

 for study. The only localities at present known are near Berry 

 Lake, at Maywood and at Joliet. The species is said to have a 

 strong fetid odor. 



SUBGENUS QONYODISCUS Fitzinger, 1833. 



"Shell: Rather small, depressed, with low but convex 

 spire and open umbilicus. Apical i^ whorls smooth, the rest 

 obliquely rib-striate, rather tubular, rounded or keeled at the 

 periphery, unicolored or flamed with reddish. Aperture wide- 

 lunate, the lip simple." 



"Animal: Long and narrow, the foot white, head and back 

 dusky blue. Sole equal in length to the diameter of the shell, 

 undivided (having a central longitudinal sulcus when entering 

 the shell or in alcohol); margins of foot having a wide border, 

 bounded by a distinct groove, the grooves meeting above the 

 tail. Upper surface coarsely granulated. Eye-peduncles long 

 and slender, from one-third to one-half as long as the foot. 

 Genital system lacking all accessory organs. The penis short, 

 having the retractor and the vas deferens inserted at its apex. 

 Spermatheca small, situated upon a very long simple duct, 

 which enters the vagina very low. At the base of the albu- 

 men gland there is a rather large talon. The albumen gland is 

 small and adherent to the lower part of the hermaphrodite 

 duct; the latter.being large and very much convoluted." (Pils- 

 bry.)* 



For radula and jaw see following species. 

 81. Pyramidula striatella Anthony, pi. xxviii, fig. 18. 



Helix striatella ANTHONY, Bost. Journ. Nat. Hist., Vol. Ill, p. 278, pi. 

 iii, fig. 2, 1840. 



Helix ruderata ADAMS, Silliman's Journ., 1st Ser., 40, 408, not STUDER. 



Helix cronkhitei NEWCOMB, Proc. Cal. Acad. Nat. Sci., Vol. Ill, p. 

 180, 1865. (Variety.) 



Pyramidula striatella catskillensis PILSBRY, The Nautilus, Vol. XI, p. 

 141. 1898. (Variety); Vol. XII, -p. 86, 1898. 



Pyramidula striatella alba WALKER, Terr. Moll., Mich., p. 22, 1899. 



Shell: Flattened, thin, widely umbilicated; surf ace covered 

 with crowded, oblique ribs, which are large and distinct, and 



"Guide to Studv of Helices, p. 46. 



