ITO 



- denticle and one proximal, 5 distal, smaller ones, the uncini (U are very slender, rather 

 long and considerably curved, one of the two rows seems to 1»- verj indistinctly denticulate 



\~> to the systematic position ol this species, I think it advisable to keep it as the type 



et a sep s, the rhachidian and lateral teeth resemble in several particulars the rïgures 



of radulae of I ithiopsis and Litiopa by Tkiwiim iCiebiss der Sclinecken PI. XI, 



fig. \i and ij l>nt the uncini seem to be more slender and are distinctly denticulate in these 



1 Argyropeza, the denticles, if they exist at all, are very faint. The operculum 



n described by Fisi her (Manuel de Conchyliologie) as suboval, paucispiral, 



with sublateral nucleus, placed at the left side of the aperture, that of Litiopa as oval, very 



thin, paucispiral. with subterminal nucleus. As stated above the operculum in Argyropeza is 



multispiral and has a subcentral nucleus. From Bit Hum, of which 1 find no description 



the radula, it should be distinguished by its many-whorled operculum. 



2. Argyropeza Melvilli n. sp. PI. XII, fig. 1. 



Suit. 102. 6°4.i X., I20°44'E. Sulu Sea. 535 M. Fine, yellow sand. 1 Spec. 



Shell small, pyramidal, white, whorls 1 1 '/,, of which nearly 2 form the nucleus. the first 

 is rather bulbous and smooth, the second radiately ribbed one is also swollen; remaining whorls 

 regularly increasing, slightly contracted above and below, nearly straight towards the middle, 

 with two spiral rows of pointed nodules, connected by slight spirals and oblique radiating ribs, 

 moreover the shell has a thin spiral, just above the linear suture. The rest of the surface is 

 smooth and shining, with a slight nacreous lustre and with numerous fine growth-striae. Body- 

 whorl conspicuously keeled below the periphery and with a second keel at some distance on 

 the smooth base. Aperture subrhombic, outer margin thin, angulate at the end of the lower 

 row of nodules, columellar margin rounded, slightly curved, ending in a point, where it joins 

 the basal margin. 



Alt. io 1 /., lat. 3 1 /,: apert. alt. r /p lat. i 1 /, Mill. 



This species has much puzzled me, more than once I had compared it with the preceding 



one, but the very different nucleus and the aperture abstained me from considering it as belonging 



to the genus Argyropeza, unfortunately the operculum and the soft parts are wanting; at last 



I asked the assistance of Mr. J. CoSMO Melvill, who suggested it would be a Cerithopsoid 



shell, probably belonging to the genus Argyropeza. As to the different nucleus, I found it had 



much resemblance with that of Cerithium obeliscoides Jeffr. (Proc. Zool. Soc. Lond. 1885, 



. PI. VI, fig. 4 . Jeffrevss (1. c. p. 59) divided the species of Cerithiopsis in two sections: 



-A. typical with acuminated apex and B. Eumeta Mörch, Apex blunt". If the species nou under 



consideration, really belongs to the genus Argyropeza, this genus could be divided in the same 



inner. I have named it after one of the authors of the genus. The new species is larger, 



with less convex whorls than A. divina, it has a nearly smooth base and quite 



different nucleus. 



62 



