144 GASTROPODA. [Aspidobranchia. 



Genus 4. CALLIOSTOMA, Swainson, 1840. 



Calliostoma, Swainson, " Shells and Shell-fish," 1840, 351: Type : Trochus 

 zizyphinus, L. Calliostoma, Swainson, Man. Conch. (1), xi, 14, 332. 

 Zizyphinus, Gray, Syn. Brit. Mus., 1840 (no description). Conulus, 

 Nardo, 1840 ; not of Fitzinger, 1833. Lischkeia, Fischer, Coq. Viv., 

 Trochus, 1880, 419. Eucasta, Ball, " Blake " Gastrop., 1889, 369. 

 Jujubinus, Monterosato, Nona. Gen. e Spec., 1884, 46. Jacinlhinus, 

 Monts., Bull. Soc. Mai. Ital., xiv, 1889, 79. Manotrochus, Fischer, 

 Manuel, 827. 



Animal having the epipodial lobes large, with 3 or 4 pairs of cirri ; 

 frontal lobes small, simple or fringed ; muzzle rather large, fringed at 

 its extremity ; tentacles long, ciliiform ; ocular peduncles distinct, 

 but short ; foot large, truncated in front ; the radula has the central 

 and 4 to 5 lateral teeth with irregularly oval body, and rather long 

 pointed cusps, their outer edges serrate ; marginals numerous, narrow, 

 with narrow serrate cusps. 



Shell imperforate or rarely umbilicate, conical, rather thin ; whorls 

 smooth, spirally ridged or granular, the last angulated at the periphery ; 

 aperture quadrangular ; columella simple, usually ending in a slight 

 tooth at the base. The operculum is thin, circular, corneous, many- 

 whorled. 



The genus is found living in all seas. 

 Fossil in the Secondary and Tertiary. 



KEY TO SPECIES. 



A. Shell small, height less than 10 mm., colour purplish-rose . . aucklandicum. 



B. Shell large, colour yellowish or brownish. 



a. Last whorl rounded et periphery, not angular . . punctulatum. 



aa. Last whorl sharply angled at periphery . . . . selectum. 



aaa. Last whorl subangular at periphery. 

 6. With finely beaded spiral lirae. 



c. 16-20 spiral lirse on the penultimate whorl . . tigris. 



cc. 8-12 spiral lirse on the penultimate whorl . . pellucidum. 



bb. Spiral ribs coarsely granose, distant, 7-8 on the 



penultimate whorl . . . . . . . . spectabile. 



1. Calliostoma aucklandicum, E. A. Smith, 1902. Plate 33, fig. 15. 



Calliostoma aucklandicum, E. A. Smith, Report on the Collections of Nat. 

 Hist., Voy. " Southern Cross," Moll., 1902, 207, pi. 24, f. 5. 



Shell small, conical, umbilicus covered, purplish, spirally lirate. 

 Sculpture consisting of spiral threads, which increase in number upon 

 the whorls with the growth of the shell ; there are 8 lira? on the pen- 

 ultimate whorl, the uppermost, or that just below the suture, some- 

 what nodose or subplicate ; body-whorl with 8 lira? above the angle, 10 

 to 11 upon the base. Colour purplish-rose ; under the lens the narrow 

 sulci between the spiral threads are seen to be of a dirty-whitish colour. 

 Spire conical, much higher than the aperture, outlines straight. Proto- 



