107 



species ; by this means the creatures are rendered uunatural, and 

 consequently dependent on man. Different varieties would doubtless 

 be produced, according to tbe manner in which they were crossed, 

 and permanent varieties would be thus established._ Such is the 

 opinion, at which I have arrived, after a long and mature considera- 

 tion of this extremely interesting subject. 



2. Descriptions of Thirty-one New Species of Land- 



ShELLS, FROM Mr. CtJMING'S COLLECTION. 



By Dr. L. Pfeiffer. 



1. Helix suBDECUSSATA, Pfr, Testaperforatū, turMuata, tetiuts, 

 irregulariter plicato-striata, superne striis spiralibus obsolete 

 decitssata, pellucida, virenti-hyalina ; spira conica, apice obtu- 

 sula ; anfr. 6 convexiusculi, ultimus non descendens, peripheria 

 subcarinatus, basi convexior, nitidus ; apertura obligua, late 

 lunaris ; perist. simplex, rectum, marginibus remotis, columel- 

 lari superne vix refiexiusculo. 



Diam. maj. 14, min. 12, alt. 9 mill. 

 Hah. Bombay. 



2. Helix grantTm, Pfr. T. perforata, turbinato-globosa, tenuis, 

 confertissime costulato-striata, pallide cornea, rufulo irregula- 

 riter variegata ; spira conoidea, acutiuscula ; anfr. b\ convexi, 

 ultinms non descendens, prope suturam turgidulus ; apertura 

 vix obliųua, late lunaris ; perist. simplex, rectum, marginibus 

 subconvergentibus, columellari vix patulo. 



Diam. maj. 4, min. 3f, alt. 3 mill. 

 Hab. New Zealand. 



3. Hel,ix fatua, Pfr. T. perforata, turbinata, tenuiuscula, ir- 

 regulanter striata, vix nitidula, fulva ; spira conoidea, acu- 

 tiuscula ; anfr. 5-a^ modice convexi, ultimus non descendens, 

 peripheria subcarinatus, basi convexiusculus ; apertura parum 

 obliąua, lunaris; perist. simplex, rectum, margine columellari 

 substricte declivi. 



Diam. maj. 5, min. A\, alt. 2\ mill. 

 Hab. New Zealand. 



4. Helix birmana, Pfr. T. perforata, depressa, suborbicu- 

 laris, tenuiuscula, ląvigata, subdiaphana, alba, fascia 1 lutea 

 supra medium ornata ; spira brevissime conoidea, vertice sensim 

 prominulo ; sutura levis, marginata ; anfr. fere 7 modice con- 

 vexi, lente accrescentes, idtimus rotundatus, non descendens ; 

 apertura vix obliqua, late lunaris; perist. rectum, intus sub- 

 incrassatum, margine dextro brevi, basali fere rectilineari, 

 superne vix dilatato. 



Diam. maj. 26, min. 23|, alt. 12| mill. 

 Hub. Mergui, Burmah. 



