1894.] L.USTD-SHELLS FROM THE SAMUI ISLANDS. 155 



ram valde constrictus, turn campanulafus, suhlcevigatus, in media 

 parte Ic^vigata obtuse cristatus. Apertura diagonalis, subcircu- 

 laris ; peristoma duplex, externum sat expansum, internum 

 continuum, valde porrectum incrassatulum, superne et basi 

 effusum et subcanalimlatum . 

 Diam. maj. 2'25, min. l'7o,alt. 1*2 millim. 



Evidently a near ally o£ the small Perak species, such as A. micro- 

 discus, in., but at once distinguished by the peculiar grooves near 

 the upper insertion and at the base of the peristome. 



29. DiPLOMMATDTA (Sinica) samtjiana, sp. nov, (Plate XVI. 

 figs. 18, 19.) 



T. dextrorsa, elongate ovato-conica, confertim costulata, pallide 

 cornea. Anfr. 7, modice convcxi, superi 5 sjnram subregulariter 

 conicam efficientes; pemdtimus magnus; nltimns angustior, paul' 

 lum distortus, initio constrictus, antice ascendens. Apertura 

 verticalis, subcircidaris ; peristoma duplex, externum modice 

 expansum, superne interruptum, internum incrassatidimi, sat 

 porrectum, basi columella angulum distinctum formans. 

 Lamella columellaris humilis, pialatalis longiuscida, subTiorizoii- 

 talis, supra columellam conspicua. 



Alt. 2"5, diam. 1"33 millim. 



Earn. PupiNiDiE. 



30. PupiNA AETATA, Bens. 



31. PupiNA PALLENS, sp. nov. (Plate XVI. figs. 27, 28.) 



T. conoideo-ovata, lewis, nitens, pallide corneo-brunnea. Anfr. 6, 

 convexiusculi ; ultimus sat distortus, supra aperturam applanatus, 

 antice breviter ascendens. Apertura paullum retrorsum incli- 

 nata, circularis ; peristoma expansiusculum, haud reflexum, 

 margo externus ad insertionem attenuatus, recedens cum lamella 

 parietali triangulari valida canalem superum formans, basalis 

 et columellaris incrassati et dilatati. Canalis inferus angustus, 

 Tiorizontalis, piostice in foramen subcirculare desinens. 

 Alt. 8, diam. 5*5 millim. 



This somewhat difficult form agrees in size with P. arula, Bens., 

 of Perak and Tenasserim, but differs in the more obtuse spire, the 

 more distorted last whorl, and consequently the aperture placed 

 more to the right and protracted at the base, the thinner outer 

 peristome, the broader columella, the broad triangular parietal 

 lamella, and the narrower lower incision. 



Eam. HyDEoaENiD^. 



32. Geobissa monterosatiana, Nev. et G.-A. 



Subsp. nov. SAMtriANA. — Minor, anfr. magis convexis. Alt. 



2'5, diam. 1"5 millim. 

 A slight niodificatiou of the Perak type. 



