CONCHOLOGY. 27 



D. octogonum. D. corneum. 



D. deforme. D. nigrum. 



D. novemcostatum. D. politum. 



D. sexangulaire. D. eburneura. 



D. striatum. D. clava. 



D. dentalis. D. fissura. 

 D. coarctatum. 



FAMILY III. 

 AMPHiTRiTiEA. Four Genera. 



1. Genus Pectinaria. PI. V. 



Animal. Respiratory organs in general known, and disposed 

 at or near the anterior part of the body ; not separated or covered 

 by an operculum. 



Shell, A membranous papyraceous tube in the form of a 

 reversed cone ; unfixed; exterior covered with sandy adhesions. 

 Two species. 



Pectinaria capensis. 



P. belgica.* 



2. Genus Sabellaria, PI. V. 



Animal. But slightly differing from the Pectinaria. 



Shell. Tubes numerous, united in a common mass, composed 

 of agglutinated particles of marine substances, cellular at the 

 base; orifice expanded. Found in the Indian Ocean, Two 

 species. 



Sabellaria alveolata. Sabellaria crassissima. 



3. Genus Terebella. Pi. V. 



Animal. Body tubicular, elongated, cylindrically depressed, 

 attenuated posteriorly ; a row of nodulous and setiferous papillae 

 on each side ; numerous filiform, twisted tentacula surrounding the 

 mouth. 



Shell. An elongated cylindrical and membranous tube with 



