92 ADDITIONS TO TIIK T\SM\M\N MARINE MOLLUBCA, 



ROYA DEVEXA, Sp. Nov. 



Shell small, white, much elevated, with a large, pro- 

 minent spiral nucleus, which projects far forward over the 

 posterior slope, and consists of three rapidly increasing 

 whorls, smooth and shining. Adult shell smooth, but not 

 shining, lamellated with growth lines, which are strongly 

 developed on the anterior slope ; there are faint indica- 

 tions of radial ridges near the base. It is possible the 

 species reaches a much greater size, and that these radials 

 would Then develop into regular ribs. The base forms a 

 narrow ovai, rather' pointed under the apex. There are 

 the remains of a thin deciduous epidermis. 



Height 5. Breadth, greatest 4-J,, least 3 mill. 



Type, with five others (all smaller), from 50-70 fathoms, 

 off Port Arthur, and an apical portion from 40 fathoms, 

 off Schouten Island. This remarkable species seems most 

 nearly related to R. violacea, Angas. 



PI. IV.. fig. 22. 



STREPHOPOMA NUCLEOCOSTATA, Sp. Nov. 



Adult shell roughly and irregularly involute in the same 

 plane, yellowish, sculpured by numerous lamellar growth 

 lines and periodic mouths. The nucleus is embraced and 

 almost concealed by the first turns of the adult. It is 

 naticoid in form, of about three turns, at first flattened 

 and smooth; axial ribs develop on the last whorl, and 

 become stronger until they reach the lip; mouth ovate, 

 much produced in front. Columella expanded over a small 

 umbilicus. Colour purplish-brown, with a golden shine. 



Dimensions of nucleus- Height 1.2. Diameter 1.5 mill. 

 Major diameter of adult about 8 mill. 



Type, from Frederick Henry Bay, fakcn from kelp roots. 

 The nucleus shell is occasionally found in dredgings. 



PI. IV., fig. 23, and PI. V., fig. 23a. 



RISSOA OBELISCUS, Sp. Nov. 



Shell small, yellowish white, elongate, narrowly pyra- 

 midal, smooth and polished ; apex somewhat bluntly cunse- 

 form. Whorls 7, slightly convex, broadest near the lower 

 suture, which is well impressed. Mouth roundly oval, 

 columella lip a little expanded over a distinct umbilical 

 chink. 



Length 2.2. Breadth 1 mill. 



Type, from 50-70 fathoms, off Port Arthur, with four 

 others; and one. from "40 fathoms, off Schouten Island. 

 It considerably resembles I', seopulorum, Watson, from 

 the Sandwich Islands. Chal. Report. PI. XLV., fig. 4. 



PI. V.. fig. 24. 



