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PYRAMIDELLIDiE. 



This family consists of a group of Gasteropoda, which, 

 so far as shell is concerned, closely resembles Bissoa and its 

 allies, consisting chiefly of turreted species, sometimes 

 smooth, often polished and shining, not a few beautifully 

 ornamented with spiral and transverse sculpturing ; their 

 apertures are entire and not produced into a canal below ; 

 many of them have plications on the pillar-lip. The 

 animal which constructs these shells is, however, very 

 distinct, being furnished with a retractile proboscis like 

 Scalaria, and having tentacles variously formed, bearing- 

 eyes immersed at their bases. The tongue is remarkable 

 for being unarmed, a character which in all probability 

 holds good throughout the tribe. The Pyramidellidfz 

 present subjects of much interest to the student of ex- 

 tinct Mollusca, numerous forms bearing all the aspect of 

 being members of this family, occurring among the fossils 

 of even the oldest stratified rocks. Many of them are 

 gigantic compared with existing species, and the group, as 

 a Avhole, may be regarded rather as appertaining to past 

 ages than to the present epoch. 



ACLIS. LovEN, 



Shell turreted, many-whorled, smooth or spirally stri- 

 ated, rarely with longitudinal strise ; mouth oval or 



VOL. HI. F F 



