^88 A MANUAL OF AMERICAN L\ND SHELLS. 



ffelix lingiiifera, Lamarck, An. s. Vert., vi, 90 (1822). — Fkuussac, Prodr., do; Hist., 

 pi. xlix, a, fig. 3.— Deshayes, Encycl. M6th., ii, 224 (1830) ; in Lam., viii, 70 ; 

 ed. 3, iii, 293. — Pfeiffer, Syinb. ad Hist. Hel , 19 (no dcscr. ). — Chenu, 

 ni. Conch., pi. xii, fig. v; pi. vii, fig. 6. — Delessert, Recueil, pi. xxvi, tig. 

 .5(1841). 



Xolotrema a2)pressa, Tryon, Am. Joiirn. Conch., iii, 50 (1867). 



Triodopsis appresm, W. G. Binnney, Terr. Moll., v, 305. 



Jn Pennsylvania and New York it is not found east of the Appala- 

 FiG. 307. chian Chain. From thence it ranges to Arkansas, fig. 308 

 and from Georgia to Illinois. It may thus be con- 

 sidered a species of the Interior Kegion. It is 

 best developed in Tennessee and Georijia. 



T. appressa, 



Animal resembling externally T. paUiata. var. a. 



Fig. 807 represents a smaller, more angular form. Fig. 308 repre- 

 sents the var. a of Say, which has two well developed teeth on the 

 peristome. I have received it from Virginia, Tennessee, Kentucky, 

 Ohio, Indiana, and Illinois. 



The jaw is very strongly arcuate, of uniform width throughout 5 an- 

 terior surface with 15 ribs, denticiilatiug both margins. 



Lingual membrane with 105 rows of 40-1-10 teeth each ; another 

 membrane (Terr. Moll., V, Plate VII, Fig. Q) had 33-1-33 teeth ; about 

 12 perfect laterals. The fourteenth tooth has a bifid inner cutting- 

 point. 



I have in my cabinet a reversed individual of var. a, found in 

 Fig. 309. my garden, in Burlington, N. J. It is a descendant of 

 some Illinois specimens sent me twenty-five years ago by 

 the lamented Kennicott. The adaptation of the species to 

 colonization is also proved by its having recently been found 

 by Mr. J. Matthew Jones in the island of Bermuda, no 

 doubt imported on plants. 



The genitalia are figured in Terr. Moll., I, Plate XI. Fig. K. The 

 ovary is long and narrow. The epididymis is very long, convoluted at 

 the end near the oviduct. The last-named organ is not much convo- 

 luted. The prostate is scalloped along its edges. The genital blad- 

 der is globular, small, with a long, small duct. The sac of the penis is 

 extremely long, ribbon-like, one and one-half times as long as the ovi- 

 duct. The vas deferens enters its apex. 



The long, ribbon-like sac of the penis resembles that figured by Dr. 

 Leidy of Mesodon Sayii. There is but little resemblance to the genitalia 

 of T. paUiata^ so nearly allied by its shell. 



