466 A MANUAL OF AMERICAN LAND SHELLS. 



Trochus terrestris, Chkmnitz. 



Helix terrestris, Pfeiffer, Mou., i, 179. 



Turricula terrestris, W. G. Binney, Terr. Moll., v, 349. 



Found in Italy, Sicily, and South of France. I have lately received 

 living specimens collected by Mr. W. G. Mazyck in St. Peter's church- 

 yard, Charleston, S. C, no doubt imported on plants. These speci- 

 mens resemble Moquin-Taudon's (Plate XX, Figs. 10, 11). 



Jaw arcuate, ends blunt, but little attenuated ; anterior surface with 

 18 stout, crowded, flat ribs. (See Fig. 508.) 



Lingual membrane : see above. 



Genital system, as figured by Moquin-Tandon, has a penis sac short, 

 stout, with a very long, flagellate extension, on the middle of which en- 

 ters the vas deferens; the retractor muscle is inserted at the com- 

 mencement of the flagellum ; the genital bladder is small, suboval, 

 with a duct three times its length and very stout ; at the entrance of 

 this duct into the vagina there are, on both sides, a bundle of (four) 

 multifid vesicles; quite near the common orifice there is a small, glob- 

 ular sac, inclosing, in place of the usual dart, a small body fringed or 

 digitated by four or five unequal obtuse lobes. 



TACHEA, Leach. 



Animal heliciform, mantle subcentral ; other characters as in Patula. 

 (See Bost. Journ. Nat. Hist., I, Plate VIII.) 



Shell imperforate, globose or subdepressed, white or yellow, orna- 

 mented with distinct bands ; whorls 5, the last convex, tumid, descend- 

 ing at the aperture; aperture broadly lunate, obsoletely angular; 

 peristome thickened, reflexed, its coluraellar margin constricted, cal- 

 lous. 



A genus of Middle and Southern Europe; one species also common to 

 America, perhaps imported by commerce. 



Our single species, T. hortensis, found only along 

 the northeastern coast, and there usuallv restricted 

 to the islands, agrees in its jaw with the other known 

 Jaw of i\icin^jortcn<.-h: gpe^ies of the subgcuus. [t is stout, arched, with 

 blunt, unattenuated ends ; anterior surface with stout, few, separated 

 ribs, denticulating either margin. 



The lingual membrane has 116 rows of 32-1-32 teeth each. The 

 centrals have a subtriangular base of attachment, so greatly are the 

 lower lateral angles expanded ; upper margin reflected ; reflection pear- 

 shai)ed, without developed side cusps, but a single stout middle cusp, 



