1879.] SHELLS FROM PERAK AND THE NICOBAR ISLANDS. 739 



vertical ; the columellar margin perpendicular, with usual tooth. 

 Peristome double, slightly sinuate on the outer margin, viewed from 

 side. 



Size, alt. 0-054, diam. 0-03 in. (G.-A.). 



Perak. (Indian Museum, Calcutta.) 



Diplommatina (Palaina) mirabilis, n. sp. (Plate LX. figs. 4, 

 4a, 46.) 



Shell dextral, solid, elongately pyramidal ; colour pale umber- 

 brown ; sculpture regular ribbing in high relief : this costulation on 

 the basal side is not continuous up to the columellar margin, but the 

 epidermal layer terminates on a denned line level with the upper 

 angle of the aperture and encloses thus a lunular smooth area very 

 characteristic of this species. Spire rapidly decreasing, sides flat, 

 apex pointed, suture well impressed. Whorls 7, the penultimate 

 the largest, sides convex. Aperture subvertical, straight on the outer 

 margin, broadly ovate ; columellar margin straight, the tooth of flat- 

 tened form. Peristome continuous, closely double. 



Size, alt. 0'07 inch, maj. diam. 004 in. (G.-A.) 



Perak. 



Of this very distinct and beautifully formed shell only one speci- 

 men was found. It presents characters which show a decided departure 

 from the subgenus Palaina ; and no doubt other allied species will 

 eventually be found in this area. 



Diplommatina (Palaina) superba, n. sp. (Plate LX. figs. 5, 

 5a.) 



Shell sinistral, elongately pyramidal, very solid ; colour ruddy 

 ochre ; sculpture fine close costulation, waved on the periphery of 

 the last whorls, the apical whorls smooth. Spire very pointed, 

 suture deep. Whorls 7'3, last very angular, almost keeled ; the ante- 

 penultimate the broadest ; the penultimate the most swollen. Aperture 

 large, circular, very oblique. Peristome much thickened, widely 

 double ; the inner lip continuous ; the outer angular on the outer 

 margin, rounded below. 



Size, alt. 0-094, maj. diam. 0-06 in. (G.A.) 



Perak. 



This is a very beautiful small species of Palaina ; only one speci- 

 men was obtained. 



(Indian Museum, Calcutta.) 



Diplommatina (Palaina) nevilli (Crosse, Journ. Conch, t. xix. 

 p. 205, pi. viii. f. 2), Lagocheilus townsendi (Crosse, I. c. p. 200, 

 pi. viii. f. 3), and Alycaus perakensis (Crosse, /. c. p 206, pi. viii. 

 f. 7) were also obtained by Dr. Townsend. 



Georissa monterosatiana, n. sp. (Plate LIX. fig. 6.) 



Testa parva, sat tenuis, imperforata, fulva ; apice Icevi, corneo at- 

 que conspicue prominente ; anfract. 5, convexi, celeriter crescentes, 

 concentrice confertimque sulcati, sulcis minutis et regularibus, 



