178 SEDENTARIA. 



sliape of a reversed cone, membranaceous or papyraceous ; 

 covered with sandy particles, and not adherent. 



Pectinaria Belyica. — The Belgic Pectinaria. Plate 

 XIX. fig. 23. Tube inversely conical, membranaceous and 

 covered with particles of sand. Inhabits the European seas. 



TRIBE III. MALDAXIA. 



With intermediate branchiae ; tube open at both ends. 



Genus 10.— DENT ALIUM.— Z?nn«MS. 



Generic Character. — Body tubicolar, conical, with the 

 anterior extremity exsertile, and surrounded by a membran- 

 ous ring; mouth terminal and naked. Tube testaceous, 

 nearly regular, slightly bent, attenuated towards the pos- 

 terior extremity, and open at both ends. 



* Tubes having longitudinal ribs or striae. 



Dentalliim elephantinnm. — The Elephantine Denta- 

 LIUM. Plate XIX. fig. 27. Green, slightly bent, with ten 

 longitudinal ribs. Three or four inches long. Inhabits the 

 Indian and European seas. 



** Tubes smooth. 



Dentalium Entalis. — The Tooth Dentaliubi. Plate 

 XIX. fig. 26. White or yellowish, slightly curved, smooth, 

 and tapering to a fine point. One and a half inch long. In- 

 habits the British seas. 



GenusU.—CCECk'LIVM.— Fleming. 

 BROCHUS Brown. 



Generic Character. — Animal unknown. Shell tapering, 

 cylindrical, subarcuated, imperforate at the smaller end; 

 aperture orbicular, placed at the large end. 



CcEcalium Trachea The Tracheiform Ccecaliubi 



