244 GASTROPODA. [PectinibrancUa. 



yellowish- white. Spire high, turriculated ; outlines Lightly convex. 

 Protoconch of 2 convex, smooth, and polished whorls. Whorls 7, 

 regularly increasing, convex, flattened towards the suture ; base 

 slightly convex. Suture impressed. Aperture subquadrangular, pro- 

 duced below into a short and open canal. Outer lip rounded, thin, 

 and sharp. Basal Up bent almost straight over towards the canal. 

 Columella vertical, straight, curving off at the base to form the inner 

 margin of the canal. Operculum unknown. 



Diameter, 1-8 mm. ; height, 4-2 mm. (shell of 7 whorls). 



Animal unknown. 



Type in my collection. 



Hab. Foveaux Strait, in about 15 fathoms. 



Fam. CERITHIOPSID^3, H. and A. Adams. 



Animal with a short, broad head ; tentacles subulate, obtuse, 

 wide at the base ; eyes placed centrally at their origin ; mouth with a 

 retractile proboscis ; tongue armed with teeth resembling in arrange- 

 ment those of Trichotropis. Mantle not reflected, furnished with a 

 rudimentary siphonal fold. Foot oblong, subquadrate in front, where 

 it is furnished superiorly with a mentum, grooved for half its length 

 below, the groove terminating in a perforation ; operculigerous lobe 

 well developed. 



The head is compressed and vertically cloven in front, and the 

 tips of the tentacles are obtuse or very slightly clavate ; the eyes are 

 placed rather close together towards the centre of the base of the 

 tentacles. (H. and A. Adams.) 



Shell small, cerithiform, canal notched at its base ; there is no 

 parietal channel. Aperture subquadrangular ; outer lip not produced 

 in front. Columella smooth, more or less twisted below near the 

 origin of the canal. Operculum suboval, paucispiral ; nucleus sub- 

 lateral, near the inner side of the aperture. 



Fossil this family first appears in the Cretaceous. 



KEY TO GENERA. 



A. Form cylindro-conic, whorls tuberculate, columella intiexed 



towards the basal notch . . . . . . . . CERITHIOPSIS. 



B. Form conic, whorls cancellate, canal strongly curved back- 



wards, columella twisted and carinated . . . . NEWTONIELLA 



C. Form cylindrical, whorls with simple spiral ribs . . . . SEILA. 



Genus 1. CERITHIOPSIS, Forbes and Hanley, 1853. 



Cerithiopsis, Forbes and Hanley. " British Mollusca," iii, 1853, 364. Type : 

 Murex tiibercularis, Montg. 



Animal with a narrow foot, subtruncated in front and attenuated 

 behind, with a longitudinal sulcus on the sole ; tentacles cylindrical, 

 the eyes sessile at their base ; opercular lobe simple, well developed. 

 Kadula with an oval central tooth, its margin dentate, a large bi- 

 cuspid lateral tooth, and unicuspid marginals with smooth margins. 



