UNIVALVES. SERPULA. 115 



spiral convolutions of its shell. The S. muricata has its 

 shell beset with a succession of spines or prickles : it is 

 usually of a rosy or pink colour, and sometimes has its aper- 

 ture margined. 



The S. cornu-copiae, or horn of plenty, is, in all proba- 

 bility, only a dropped Helix nemoralis, or common garden 

 snail, and of course not belonging to this genus. The S. 

 denticulata is sometimes found in the Lepas tintinnabu- 

 lum; and the S. granulata adheres to the roots of the fucus 

 digitatus ; the S. retorta is retort shaped; the latter is scarce. 

 The S. incurvata partially resembles the Nautilus semili- 

 tuus, but it wants the internal concamerated structure. 



The colours of the Serpulae are various; the most gene- 

 ral, however, are brown, purple, yellow, tawny, pink, and 

 white, sometimes a little greenish. 



The Indian, African, American, and Northern oceans 

 supply many species; as also do the European, Mediter- 

 ranean, Adriatic, and Red seas. 



SERPULA Worm- Shell. 



DIVISION I. Attached to other substances. 

 Spirillum Minute Spiral. Glomerata Glomerated. 



Triquetra Three-sided. Conica Conical. 



*Intricata Intricate. *Vermicularis Round. 



*Corrugata Wrinkled. *Tubularia Tubular. 



Contortuplicata Twisted. Denticulata Toothed. 



Goreensis Goree. Ocrea Boot-shaped. 



Gigantea Great. 



Minute Shells. 



Stellaris Rayed pin's-head. Granulata Grained. 

 Planorbis Flat. Cancellata Grooved. 



Minuta Minute. *Heterostropha Reversed. 



Spirorbis Tapering. *Lucida Shining. 



Carinata Keeled. Vitrea Glossy. 



