HELIX §. iO. 49 



Helix demissa (Ilyaliua) P/?\ Vers. p. 123. 

 Ilelicella demissa H. ct A. Adams Gen. II. p. 118. 



Habitat in parte occidentali Pennsylvaniae. 



Obs. Persimilis //. Hnldemanianap, sed perforata : nec non H. ligerae, 

 sed depressa. 



*- 



278. succinea Pfr. (Coll. 109. Rv. n. 161. t. 36. — 

 Nanina succinea Gray Cat. Pulnt). p. 102. — 

 Microcystis Ad. Gen. p. 224. — Xesta Pfr. Vers. 

 p. 120.) Mon. III. p. 63. 



'279. rustica Pfr. (Coli. 110. — H. inconspicua Forb. 

 — H. impexa Rv. n. 795. t. 130. — Nanina 

 rustica [Xesta] Pfr. Vers. p. 120.) - - - 63. 



280. Perrotteti Pfr. (Co!l. 111. — Ch. ed. nov. III. 



p. 487. — Rv. n. 1414. t. 201. — Nanina 

 PeroUeti Gray Cat. Pnlm. p. 83. — Xesta Pfr. 

 Vers. p. 120.) - - - 63. 



281. nitella Wlor. f - - 64. 



2S2. H. vilipcnsa Bcnson. -^ 



«T. aperte perforata, pervia, depressa, solidiuscula, pel- 

 ucida, cornea, polita; spira convexiuscula, sutura vix margi- 

 nata, apice obtuso; anfr. 5 subplanulatis, lente accrescentibus, 

 ultimo rolundato, subtus convexiusculo; apertura late lunata, 

 subobliqua; perist. recto, acuto, margine columellari oblique 

 descendente, expansiusculo, superne breviter reflexo; umbilico 

 pervio. — Diam. maj. 8, min. 7, axis 4 mill. » (B.) 



Helix vilipensa Bens. in Ann. and Mag. N. II. 2d. ser. XII. p. 93. 



Habitat ad rupem MehiQtali insulae Geylon (Layard). 



283 H. umbrina Pfr. 



T. vix perforata, depressa, tenuis, levissime striatula, niti- 

 dissima, umbrina; spira vix clevata, vertice subtili, obtusulo; 

 sutura levis, marginata; anfr. 4^2 convexiusculi, sensim accre- 

 scentes, ullimus depressus, non descendens, basi subplanulatus, 

 medio excavatus, angustissime perforatus; apertura parum ob- 

 liqua, lunaris; perist. rectum, acutum, marginibus distantibus, 

 columellari oblique descendente, superne supra perforationcm 

 breviter reflexo. — Diam. maj. 7, min. 5%, alt- 3 mill. (Coll. 

 Nr. 112.) 



Helix imbrina Pfr. in Proc. Zool. Soc. 1853. (casii omissa.) 



— — Reeve Conch. ic. n. 1335. t. 190. 



Nanina mnhrina (Xesta) Pfr. Vers. p. 120. 



Habitat in insula Ceylon (Thwaites). 



IV. 4 



