MUSEUM OF COMPARATIVE ZOOLOGY. 191 



In studying the lingual membrane of many individuals of M. Andrewsi, I 

 have found some variation. I give here notes on membranes of specimens 

 labelled as specified in the Binney collection in the United States National 

 Museum. 



AA. 60-1-60 teeth, with about 14 laterals on each side. 



N. 51-1-51 teeth, with 11 laterals ; some extreme marginals have decid- 

 edly multifid cusps. 



Q, from Hayesville, N. C, has also about 11 laterals. 



V has 9 laterals, 60-1-60 teeth. 



M. 60-1-60 teeth, with about 14 laterals. Some outer laterals have side 

 cusps : one is figured on Plate I. Fig. 12. 



G has same count as M; no side cusps to outer laterals. 



N has 64-1-64 teeth, with 14 laterals. The extreme laterals have side 

 cusps. 



L has 61-1-61 teeth, with 11 laterals ; no side cusps on outer laterals. 



J same. 64-1-64 teeth, with 14 laterals. 



B. 60-1-60 teeth, with 16 laterals, none with side cusps. 



F. All laterals, even first, have decided side cusps (see Plate I. Fig. 10) 

 and cutting points: and marginals also (Fig. 11). 50-1-50 teeth, with 15 

 laterals. 



K. 53-1-53 teeth, with 14 laterals. 



I. 50-1-50 teeth, outer laterals with side cusps. 



0. 68-1-68 teeth, with 14 laterals. 



As remarked above, most collectors will refer this large form of Andrewsi to 

 major. It differs from that species as hitherto understood very decidedly 

 in its lingual dentition and genitalia. In its shell, also, the species differs 

 from the generally known major in so marked a manner, that from it alone I 

 could say, before examination, what were the characters of the dentition and 

 genitalia of every specimen collected by Mr. Hemphill in the mountains of 

 North Carolina. One of the puzzling questions to be left to future solution is 

 the limitation of albolabris, major, and Andrewsi. It must be studied from the 

 lingual dentition and genitalia, as well as from the shell. The student must 

 also consider whether the Helix major of the Boston Journal and of the Ter- 

 restrial Mollusks are the same species. 



Practically, the simplest way of treating specimens in collections is to refer 

 to a variety of albolabris all forms more resembling that species than they do 

 the major of the Terrestrial Mollusks, and to call major all specimens most 

 nearly conforming to the figure and description of that species in Terrestrial 

 Mollusks of U. S., Vols. II. and III. In the former category would be placed 

 the major of the Boston Journal ; in the latter, the large forms I have referred 

 to Andrewsi in Manual of American Land Shells, such, for instance, as are fig- 

 ured in Fig. 322£, repeated here, ante, page 190. This variety of albolabris 

 and this major, as above identified, would be found to differ widely in den- 

 tition and genitalia, the former in these respects resembling albolabris, the 



