178 SEDENTARIA. 



shape 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. MALDANIA. 



With intermediate branchiae ; tube open at both ends. 



Genus 10.— DENTALIUM.— Zmn^ws. 



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 strias. 



Dentahum elephantinum — 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 Entails. — The Tooth Dentalium. 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. 



Genus U.—C(ECALIJ]M.—Flemmff. 

 BROCHUS— ^/o^xTi. 



Generic Character. — Animal unknown. Shell tapering, 

 cylindrical, subarcuated, imperforate at the smaller end ; 

 aperture orbicular, placed at the large end. 



Ccecalium Trachea The Tracheiform Ccecalidm 



