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 Scyllasa pelagica (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- 

 cheUa of Alder and Hancock. 



Genus II. HEEO [*], Loven. 



BODY limacifonn : 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. 



Clatlia formosa, Lov6n in Ofv. K Vet. At. 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 umbellated form, with truncated 



[* A mythological name.] 



