226 Mr. Cosmo Melvill oji the 



{b) argella (van nov.). Shell usually oblong-ovate, sides 

 not thickened, colour orange-brown, entirely enveloping the 

 surface, the star like white dots appearing clearly defined 

 over the back, the effect being exactly antagonistic to the 

 normal condition, where brown specks appear on the dorsal 

 surface on a greenish or bluish-white ground. I have four 

 specimens of this variety, and have seen many others. 

 Habitat, with the typical form. 



if) Hazuaiiensis (van nov.), (fig. i8). Pellucid, shining,, 

 straw-coloured on both sides. There are two forms of this 

 well-known variety, one incrassated laterally, bearing a 

 strong superficial resemblance to C. cernica (Sowb.), the 

 other with straight sides. Often the extremities, of so con- 

 spicuous a lilac in this type, present a pale reflection of that 

 colour ; otherwise they are uniformly straw-coloured. From 

 the Sandwich Islands. Also cf. Sowb., T. C, pi. xxv., f 217. 



C. poraria (L.). Type Sowb., Thes. Conchyl., pi. xxvi., . 

 f 236 — 237. An abundant Eastern shell. The lilac-backed 

 unspotted young shells are very bright and beautiful. A 

 curious monstrosity is mentioned by Brazier {Proc. Linn. Soc. 

 NS. IF., VI., p. 202), destitute of white dots, and with the 

 aperture shaped liked the figure 8. 



(a) Kanaiensis (van nov.). Pellucid. Pale yellow with 

 purple tinge. From Kauai I., Sandwich Isles. Another 

 of the characteristic Sandwich Island varieties. 



C. Laniarckii (Grdiy). Reeve., C. Icon., pi. x., f "^y., Sowb., 

 Thes. Conch., pi. xvii., f 106, 107. Shell ovate, somewhat 

 ventricose, slightly prolongated at either extremity, pitted 

 at the sides, teeth about sixteen on either side, back ochreous,, 

 profusely dotted with large and small round white spots, 

 some of them ocellated, but occasionally with no signs of 

 ocellation, extremities lineated as in C. turdus and C. 

 erosa. Sides scarcely thickened, brown-spotted. Length 

 i^ in., lat. ]/Q inch. Locality, Mozambique, &c. 



{a) redUnita (van nov.), (fig. 16). Shell somewhat stout, 



