AMPHIDKOMUS. 187 



a. Periphery rounded ceylanicus. 



b. Periphery angular. 



6 1 . Shell elongate-conoid, whorls convex .... intermedius. 



6 2 . Shell pyramidal, whorls flattened physalis. 



c. Periphery strongly carinate. 



c 1 . Dextral ; Ceylon albizonatus. 



c a . Sinistral ; Southern India cakadensis. 



159. Amphidromus trifasciatus, Gmelin. 



Helix trifasciatus tranquebarica, Chemnitz, Conch.-Cab. ix, part 2, 



1786, p. 155, pi. 134, figs. 1215. 



Helix trifasciata, Gmelin, Syst. Nat. i, part 6, 1790, p. 3642. 

 Bulimus trifasciatus, Bruguiere, Encycl. Me*th., Vers, i, 1789, 



p. 317; Reeve, Conch. Icon, v, Bulimus, 1848, pi. 39, fig. 237; 



Pfeiffer, Conch.-Cab., Bulimus, 1853, p. 50, pi. 10, figs. 6, 7, var. 



pi. 41, figs. 16, 17 ; Layard, A. M. N. H. ser. 2, xi, 1853, p. 226; 



Hanley & Theobald, Conch. Ind. 1870, pi. 21, fig. 3. 

 Bulimus (Amphidromus) trifasciatus, Pieiifer, Malak. Blatt. ii, 1856, 



p. 147. 

 Buliminus ( Cerastus) trifasciatus, von Martens, Die Heliceen, ed. 2, 



1860, p. 232; Nevill, Hand Liot, i, 1878, p. 132. 

 Amphidromus trifasciatus^ Jousseauine, Me*m. Soc. Zool. France, vii, 



1894, p. 295. 

 Buliminus (Beddomea) trifasciatus, Kobelt, Conch.-Cab., Fam. Buli- 



minidae, 1900, p. 677, pi. 102, fig. 22. 

 Amphidromus (Beddomea) trifasciatus, Pilsbry, Man. Conch, eer. 2, 



xiv, 1901, p. 3, pi. 1, figs. 1-6, 8. 

 Ehachis trifasciata, Kobelt & Mollendorff, Nachr. D. Malak. Gesells. 



1903, p. 39. 

 Bulimus ceylanicus, Hanley & Theobald, Conch. Ind. 1870, p. ]1, 



pi. 21, fig. 2 ; 1875, p. 59, pi. 148, fig. 9. 

 Buliminus (Beddomea) ceylanicus, Kobelt, Conch.-Cab., Fam. Buli- 



minidae, 1900, pi. 103, figs 5, 6. 

 Amphidromus (Beddomea) ceylanicus, Pilsbry, Proc, Malac. Soc. 



London, iv, 1901, p. 159, pi. 16, fig. 3 (jaw). 

 Bulimus fuscoventris, Benson, A. M. N. H. ser. 2, xviii, 1856, p. 96 



(=juvl). 



" T. umbilicata, ovato-oblonga, solidula, minutissima striatula, 

 nitida, albida, fulvido-nebulosa, fasciis pluribus (plerumque 3) 

 castaneis ornata; spira conica, acutiuscula; anfr. 6 planiusculi, 

 ultimus ^ longitudinis sequans ; columella subrecta ; apertura 

 oval is ; perist. album, late expansum, margine columellari dilatato, 

 patente." (Pfeiffer.) 



" Long. 27, diam. 13 mill. Ap. intus 11 mill, longa, 7 lata." 



Hob. India : Tranquebar (Chemnitz) [?]. Ceylon : Tamanka 

 (Layard)-, Matella, Colombo, Uda Pussellawa (Collett). 



The species varies in size. I possess specimens 30 mm. long, 

 16 mm. in diameter. One has the upper two bands confluent, 

 forming a broad zone which ascends the whole spire ; another 

 shows one distinct narrow band, with two indistinct ones on 

 either side on the upper portion of the latter part of the last whorl, 



