LOCALLY INTHODl'CKD SPECIES. 



467 



half as loug as the base of attachment, and bearing a short, conical cut- 

 ting point, reaching only about one-half the distance to the lower edge 

 of the base of attachment; fig. 510. 



this cutting point has lateral 

 bulgings. First laterals like 

 the centrals, but asymmet- 

 rical by the irregular cut- 

 ting away of the lower inner 



angle of the base of attach- Lingual dentition T. hortemis. (Morse.) 



meut; outer laterals with a more developed cutting point and a de- 

 cided side cusp and cutting point ; the change from the laterals to the 

 marginals is shown in the sixteenth tooth in Morse's figure in L. & Fr.- 

 W. Sh., I, in the eleventh in the membrane figured by me, where the 

 base of attachment is wider, the reflection stouter, and the inner cut- 

 ting point becomes bifid. The marginals are low, wide, the reflection 

 equaling the base of attachment, the inner cutting ijoint short, bluntly 

 bifid, the outer shorter and blunt, often bifid (Terr. Moll., V, Plate X, 



Fig. C). 



Tacliea liorteiisis, Muller. 



Shell imperforate, subglobose ; epidermis shining, smooth, olivace- 

 ous-yellow, and often variously ornamented with rufous ^'f- ^^1 

 horizontal bands or lines ; whorls 5, convex; sj^ire some- 

 what elevated ; suture, at the extremity of the last whorl, 

 curved towards the aperture ; peristome slightly reflected, 

 white, obsolete on the base, with the margin thickened 

 internally ; aperture rounded, slightly contracted at the base by the 

 thickening and indentation of the peristome; umbilicus covered, in- 

 dented ; base convex. Greater diameter 20, lesser 17"" ; height, 12'"'". 



Helix hortensis, Muller, &c. — Pfeiffer, Mod. Hel. Viv., iii, 195. — Mrs. Sheppard, 

 Tr. Lit. Hist. Soc. Quebec, i, 193 (18-.i9).— Gould, Invert., 172, ed. 2, 429 

 (1870).— BiNNEY, Terr. Moll., li, 111, pi. viii.— W. G. Binney, Terr. Moll., iv, 

 51 ; L. «fe Fr.-W. Sh., i, 181 (1869).— Morse, Amer. Nat., i, 186, fig. 16 (1867). 



Helix suhgloiosa, Binney (formerly), Bost. Journ. Nat. Hist., 1, 485, pi. svi (1837). — 

 De Kay, N.Y.Moll., 33, pi. ii, fig. 14; pi. iii; fig. 39. 



Tachea horfcnsis, Morse, Journ. Portl. Soc, 1, 10, fig. 11 ; pi. iv, fig. 12 (1864). — Tryon, 

 Am. Journ. Conch., ii, 321 (1866).— W. G. Binney, Terr. Moll., v, 379. 



A European species, introduced by commerce (*?) to the northeastern 

 portion of North America. It is found on islands along the coast from 

 Newfoundland to Cape Cod, and on the mainland plentifully in Gaspe, 

 Canada East ; also along the Saint Lawrence, Vermont (?), Connecticut 



T. hortensis. 



