1869.] Descriptions of marine Gastropoda from Ceylon, fyc. 159 



liter minute sulcatis : sulcis liris depressis latioribus, cequi-distantibus 

 separatis ; ultimo anfractu maximo, ad periplieriam angulato ; basi 

 leviter convexa, spiraliter striata, profunde et anguste umbilicata, in 

 excavatione umbilici albida ; apertura oblique quadr angular i, intus 

 callositate moderata ac loevi instrueta ; labro ad marginem sub-obtuso, 

 labio prope recto, albido, antice truncatim desinente. 



Alt. 6| Mil. — Diam. maj. 5 Mil. 



Not uncommon, in the same places as the preceding. 



This pretty little species varies immensely, not only in colour and 

 size, but also as regards the convexity of the whorls and the angle of 

 the spire. There are specimens from Arakan and from the Anda- 

 mans, in the collection of Dr. Stoliczka, after whom the species is 

 named, and who kindly assisted us in drawing up the descriptions of 

 the species noticed in this paper. 



Gibbula ? sub-plicata-N. S., Pi. XVII, Fig. 1. 



T. turbinata, tenuis, semipellucida, alba ; anfractibus quinis, tubulo- 

 sis, ad suturam applanatis, spiraliter costulatis : costulis in anfractu 

 pemdiimo tribus, omnibus valde prominentibus, intersfiis profundis, 

 distantioribus separatis, in anfractibus superioribus transversaliter 

 cancellatis seu scrobiculatis, in ultimo spiraliter subtilissime striatis ; 

 anfractibus omninis ad suturam transversaliter plicatis ; basi sub- 

 convexa, anguste umbilicata, quatuor costulis spiralibus omata, intersfiis 

 duobus, prope umbilicum sitis, transversaliter costulatis ; apertura fere 

 circulari, margine simplici circumdata, labio moderate insinuato ; 

 superjicie interna, paululum margaritacea. 



Alt. 5 Mil.— Diam. maj. 4 Mil. 



Rare ; — S. Prov. Ceylon. 



There is some difficulty in determining in what genus, or sub-genus 

 to place this curious little species, the thinness of shell and the peculiar 

 sculpture of the body-whorl, as well as the slightness of the internal 

 pearly layer, make its position, as long as the animal and operculum 

 are unknown, somewhat doubtful. 



Tallorbis— N. Sub-G. 



T. sub-orbiculata, subconica, columella solidd, antice applanatd, 

 transversaliter plicata et abrupte termiata instrueta ; habitu generi, 

 Thalotia dicto, affinis. 



We experience some considerable difficulty in determining the exact 



