of North American Helicidm. 431 



Remarks. — This species has been confounded with II. Edgar- 

 iana Lea, from wliich, however, it differs in several well 

 marked characters. The specimens to which Mr. W. G. Bin- 

 ney refers (Terr. Moll. lY., p. 65), as being of Lea's species, 

 are of that now under consideration. 



The thickened and reflected peristome, and deep wide notch, 

 sufficiently distinguish H. labrosa from II. Edgariana. The 

 notch in the latter, situated in the centre of the aperture as in 

 H. stenotrema., is in a measure obsolete, but in H. lahrosa it is 

 strongly developed, and nearer to the outer edge of the peri- 

 stome as in II. hirsuta. The form of the parietal tooth of my 

 species is like that of II. hirsuta.^ while H. Edgariana is in that 

 particular more like II Uenotreina. 



II. Edgariana., in fact, connects II stenotrema with H. spi- 

 nosa, but //. labrosa is rather allied to H. hirsuta, and in the 

 character of the peristome to H. maxiUata Gould. 



W. G. Binney has a pale, thin, apparently immature spe- 

 cimen of 77. labrosa, entirely agreeing with it as above described, 

 excepting that the lower lip is not thickened. 



Helix iiionodoEi Rackett. 



There appears to be no doubt that H. fraterna Say is a vari- 

 ety of this species ; the degree to which the umbilicus is open 

 is very variable, it is comparatively rarely entirely closed. 

 The parietal tooth is sometimes much elevated, approaching in 

 form to that of II. hirsuta, I have several specimens in which 

 the lower lip is continued as in the typical form, so as partially 

 to cover the umbilicus, but in a subsequent stage of growth has 

 its columellar termination duplicated, recurved, and united to 

 the parietal tooth. Occasionally there is a callus, having the 

 appearance of an incipient tooth, on the inner margin of the 

 outer lip. 



The following are measurements of specimens in my cabi- 

 net. 



DEC. 1S61. 30 Ann. Ltc. Nat. Hist. Vol. VIL 



