184 INVERTEBRATA OF MASSACHUSETTS. 



smoky horn-color, its constant umbilicus, its rather thick and 

 shining lip, and its whitish wrinkles, which, instead of being 

 remote, are crowded as in other species. From H. arborea it 

 differs in having one whorl less, the last one dilating ; its apex 

 not being depressed, its thinner, more shining structure, and its 

 somewhat smaller umbilicus. In H. arborea the outer lip has a 

 flexuous curve, but is nearly a direct section of the whorl in this. 

 Though all of the same size and general appearance, the three 

 may be readily separated, when seen in company. Indeed, its 

 claims as a distinct species are not very obvious without viewing 

 the three together. It may be briefly described by saying, that it 

 resembles H. indentata above, and H. arborea beneath. 



This shell was first discovered by Mr. T. J. Whittemore, about the 

 borders of Fresh Pond, in Cambridge, where it has since been found 

 abundantly by him and by myself, under fragments of board in damp 

 places, near the water's edge, in company with H. chersina and Pupa 

 modesta. I have never seen it in company with either H. indentata 

 or H. arborea ; and it seems to differ widely from them in its habits, 

 in thus preferring the vicinity, and even the intrusion, of water. Pro- 

 fessor Adams informs me, that he has selected numerous specimens of 

 this species from among small snails collected by him in Missouri. 



HELIX LABYRiNTHICA. 



Shell minute, conic-globose ; whorls six, with conspicuous oblique 

 lines ; lip reflected ; aperture with one or two teeth prolonged within 

 it ; umbilicus minute. 



FIGURE 106. 

 State Coll., No. 109. Soc. Cab., No. 1030. 



Helix labyrinthica, SAY; Journ. Acad. Nat. Sc., i. 124. Nicholson's Encyc., 

 (Amer. cd.)> i*. FERUSSAC ; Hist. Nat. des Moll., pi. 51 B. f. 1. BINNEY ; 

 Bost. Journ. Nat. Hist.j iii. pi. 24, f. 1. 



Shell small, rounded-conical, apex obtuse ; spire elevated, 

 whorls six, separated by a well-marked suture, with conspicuous, 

 oblique lines or ridges at regular distances ; epidermis dark 

 brownish horn-color ; aperture small ; outer lip thickened, and 

 somewhat reflected, often rose-colored ; inner lip with a long, 



