HERO. 63 



cylindrical stem, giving off numerous branches; there are 

 6 or 7 in single series on each side : foot narrow, rounded in 

 front, with the sides thin and formed for clasping. L. 1-2. 



Habitat: On most parts of our coasts, from low-water 

 mark to deep water, not uncommon. Its range extends 

 northwards to the Scandinavian and Greenland seas ; and it 

 is also met with on the Atlantic coast of North America. 

 [North of France, as /S'('2/7/(«a^>t'?^ry<ca(Bouchard-ChantereauX;, 

 fide Fischer) ; Brittany (Cailliaud).] 



This beautiful mollusk varies a good deal in size as well as 

 in colour. A white variety is the Tritonia lactea of Thompson ; 

 and a small variety of a delicate pink colour is the T. pul~ 

 chdla of Alder and Hancock. 



Genus II. HERO [*], Loven. 



Body limaciform : tentacles linear, smooth, without sheaths ; 

 head with a plain veil : branchial processes branched or um- 

 bellated, set in single series on the sides of the back : odonto- 

 phore with a large denticulated central spine, and 2 simple 

 lateral ones. 



This genus was first described by Professor Loven under 

 the name of Clcelia ; but finding that that name had been 

 before used to designate more than one genus in zoology, he 

 subsequently changed it to Hero. 



Hero formo'sa^ Loven. 



Clcelia formosa, Loven in Ofv. K. Vet. Ak. Forh. 1844 ; Index Moll, 

 Scand. p, 7. 



Body rather slender, transparent white or of a pale rosy 

 hue, with three lines of opaque white (one on the back and 

 one along each side) : head-veil expanded, arched, notched in 

 front, and produced and curved at the sides : tentacles linear, 

 slender, smooth ; branchial processes pedunculated, and branch- 

 ing laterally at the top in an urabellated form, with truncated 



[* A mythological name,] 



