99 



which, as in Voluta, opens into the floor of the buccal mass in 

 front of the odontophore. 



The radula of Volutilithcs exhibits three teeth in each transverse 

 row. Of these rows there are about no, but owing to the small 

 size of the teeth the radula is small and delicate. The central 

 tooth is tricuspid, the laterals uuicuspid. 



For further remarks upon this interesting- mollusk see Prjc. 

 Malac- Soc. vol- iv. pp. 122-124. 



Conchologically, this genus is ^■ery closely rdaled to / ^ohitn. 

 The tricuspid rhachidian tooth is similar to that of most of the 

 Volutidac (as far as known), which, however, unlike this, have no 

 laterals. Having regard to this difference, and to certain differ- 

 ences in the anatomy, the propriety of retaining VoUiliUthcs as a 

 genus distinct from T'oZ/z/a is established, and Air. Woodward 

 even suggests a doubt as to whether it may not be regarded as 

 representing a family apart from the Volutidac- 



VoLUTiLiTHES GirxiiRiSTi, u. sp. (Plate TL, fig. 5). Shell ob- 

 long ovate, yellowish white, surface cancellated; spire rather 

 shortly conical; whorls rather convex, longitudinallv ribbed, and 

 spirally lirate, separated by a deeply channelled suture. abo\e 

 which the top of the whorl projects in an acute crenulated ridge; 

 last whorl about two-thirds the entire length of the shell, convex, 

 and but shghtly attenuated towards the base, with;a narrovish 

 concave depression a little below the sutural ridge; longitudinal 

 ribs about 16. elevated at the suture, and gradually becoming 

 obsolete towards the base; spiral lirge rather narrow, becoming 

 stouter towards the base. Aperture narrowly oblong; columella 

 covered with a thick callus; plicae 6, very small and faint, the 

 anterior one heinof more prominent, than the rest, oblique, thin and 

 sharp; outer lip very thick, smooth and rounded, forming on the 

 exterior a broad, slout border to the whori, as in the genus 

 Margiiiclla. " ; 



Length 30; breadth 15 millim. 



Hab. : — Cape Natal W. by N., distant 11 miles. Depth, 200 fms. 



Pi.KUROTOMA GiLciiRisTi, n. Sp. (Plate II. fig, 9), Shell elon- 

 gatel\- fusiform, posterior longer than the anterior, whitish tinged, 

 and banded with pale yellow- Spire elongately turreted. slightly 

 convex at the sides, acute at the apex ;' whorls 12. apicafones 

 smooth, rounded, regular, the rest sloping, scarcely conve.x:, with 

 a double keel above, beneath which is a deepish rut, and about 

 the middle of the whorl a stouter keel ornaniented with ratlrer 

 close-set. gem-like tubercles, the interstices between the keels 

 being ridged and grooved ; suture of the upper whorls trans- 

 versely plicate, and of the lower narrowly Ccinaliculate. Last 

 whorl rather convex with the tubercles, becoming longitudinally 

 narrower, and the keel bearing them less prominent. l)eneath 

 which there arc several acute keels and intervening lirns; the 



