15 



Tube striated, or ribbed longitudinally. 



Dentalium elephantinum Dentalium octoganum 

 aprinum novemcostatum 



fasciatum dentalis 



Tube without ribs or longitudinal stria. 



Dentalium entalis Dentalium nigrum 



tarentinum politum 



corneum eburneum 



W- ; 



PECTIN ARIA. 



AMPHITRITE AURICOMA. 



Muller, p. 26, pi 26. 

 A membranous, or papyraceous tube, in the form of a 

 reversed cone, not fixed to one spot, the exterior with 

 adhesions of sand. 



Pectinaria Belgica Pectinaria capensis. 



SABELLARIA. 



SA BELLA ALVEOLATA. LinnCBUS. 



Is nearly allied to the preceding species: the animal 

 however, differs; the tubes are cellular at the base, the 



