14 CONCHOLOGY. 



3. Terebella. Three species. 

 Tube elongated, cylindrical, membranous, attenuated and 

 pointed at the base, with adhesions of sand. 



Terebella conchilega. Terebella cristata. 



T. ventricosa. 



T. conchilega. The shelly Terebella. 



Tube covered with numerous fragments of broken shells. 



4. Amphitrite. Six species. 

 Nearly the same as the Terebella, but of a tougher mem- 

 branous texture, and generally without adhesions. 



Amphitrite ventilabrum. Amphitrite vesiculosa. 

 A. penicillus. A. volulacornis. 



A. magnifica. A. infundibulum. 



A. ventilabrum. The Fan Amphitrite. 

 Tube subulate, smooth, of a yellowish colour. 



FAMILY It, 



SerpuLacea. Five genera. 

 1. Spirorbis. Five species. 

 Tube testaceous, spirally twisted on a horizontal plane, 

 with terminal aperture rounded or angular, attached by the 

 lower part to marine substances. 



Spirorbis Nautiloides. Spirorbis carinata. 



S. spirillum. S. lameliosa. 



S. tricostalis. 



S. Nautiloides. The Nautilus-shaped Spirorbis. 

 White, transversely wrinkled and minute. 



2. Serpula. The Worm Shell. Twenty-six species. 



The name of this genus is derived from the Latin word 

 serpo, to creep, on account of the vermiform character of 

 some of its species. 



They are invariably tubular, sometimes solitary, but more 



