154 an. o. r, vox moellendoeff on [Peb. 20, 



the peristome, the inner yelloAv or orange lip contrasting with the 

 white outer one, the widening of the peristome to the right, &c., 

 must be analogous according to Pfeiffer's description. 



26. Lagocheilus lieatulus, sp. nov. (Plate XVI. figs. 25, 26.) 



T. anguste umhilicata, turJnnata, sat tenuis, nitichila, transverse 

 subtiliter striatula, lineis sjnralibus elevatis sat confertis usque 

 ad umhilicum dncta, corneo-jlava, obsolete strigata. Anfr. 5A, 

 conve.vi ; ultimus antice paullum desceiidens. Apertura sat 

 obliqua, fere circulans ; peristoma subduplex, tenue, breviter ex- 

 pansum, haud rcjiexum, ad insertionem breviter excisum. 

 Diam. maj. 5, min. 4'25, alt. 5 millim. 



Differs from L. townsendianus, Crosse, of Perak, in the smaller 

 size, the higher and more pointed spire, the more convex whorls, 

 the narrower umbilicus, the want of angulation in the last whorl, 

 and the equally distant, uniform spiral lines. 



Fam. DiPLOMMATINIDJE. 



27. AlxCjEus koebeleni, sp. nov. (Plate XVI. figs. 20, 21.) 



T. modice umbilicata, subdepresse turbinata, tenuis, pellucida, 

 costulo-striata, lineis spiralihus microscopicis deeussata, Icete 

 Jlava ; spira modice elevaia, lateribus subconcavis, apice obtusulo 

 glabrato. Anfractus 5, perconvexi, ad suturam p)'rofunde im- 

 pressam subplanati ; ultimus postice spiram altitudine midto 

 superans, valde injlatus, gibber, 4 millim. pone aperturam valde 

 constrictus, turn denuo dilatatus, ad aperturam sat dcflexus. 

 Apertura diagonalis, subeircularis ; peristoma continuum,, vix 

 duplicatum, sat expansum, haud reflexum, jlavo-labiatum. 

 Operculum corneum, valde concavum, anfr. 6. Tubulus suturalis 

 brevis, appressus. 



Diam. maj. 9*5, alt. 7 millim. 



Var. minor : spira paullo magis elevata. Diam. 8'5, alt. 7 

 millim. 



Although nearly related to A. peral-ensis, Crosse, this form must, 

 I think, be separated specifically. It is larger, much less elevated, 

 more widely umbLhcated, the last whorl comparatively higher, 

 about four-seventlis of the total altitude, and much more tumid, more 

 deflected at the end, and therefore the plane of the aperture much 

 more oblique, the constriction deeper, the peristome hardly double, 

 not so thick, and yellow instead of white. Besides there is half 

 a whorl less, as I count distinctly 5| in A. perahensis. Unless 

 transitory forms exist in the, as yet, little-explored Malay Peninsula, 

 I think these differences sufficient to consider the Samui race a 

 distinct species. 



28. Altc^tjs canaliculatus, sp. nov. (Plate XVI. figs. 22, 23.) 



T. sat aperte umhilicata, depressa, solidula, confertim costidata, 

 pallide cornea j spira parum elevata, convexo-conoidea. Anfr. 

 3|, convexi ; ultimus a medio injlatulus, subgibber, pone apertu- 



