60 



POPULAR CONCHOLOGY. 



The species of this genus are found in the eastern and 

 tropical seas, many of them being abundant at Java. P. 

 Babylonica and grandis are two of the most striking ; but 

 there are many of very elegant forms. 



Perrona. Schum. — Shell spindle-shaped, prolonged 

 into a canal at the base ; the outer lip has a slit, and be- 

 tween that and the canal a sinus. The animal has an 

 operculum. — 2 species. 



The Pleurotoma spirata and lineata of Lamark form this 

 genus. 



Clavatula. Lam. — Shell greatly re- 

 sembling Pleurotoma, but having a very 

 short canal ; the right lip has a sinus parallel 

 to the suture ; the upper part of the whorls 

 are tuberculated or spined. The animal 

 forms an operculum. 



Founded on Pleurotoma auriculifera, &c. Clc pa&* 



Defrancia. Millet. — Shell turreted, with a 

 short distinct canal ; the aperture long, oval ; the 

 outer lip divided from the suture by a sinus. 

 Animal, having the foot truncated, prolonged on 

 each side into a hook ; no operculum. 



Founded on Pleurotoma harmila. d 



1 linearis. 



Daphnella. Hinds. — Shell thin, fragile, elongated in 

 form, the outer lip acute, and separated from the last 

 whorl so as to leave a sinus ; aperture of a lengthened 

 oval, scarcely any canal, and with the surface usually 

 transversely striated. Animal, not known. 



This genus appears to be separated from Defrancia by 

 the almost complete absence of a canal. The type is 

 Pleurotoma linnceiformis. Kien. 



Mancelia. Risso. — Shell fusiform, longitudinally 



