360 



A. E. Verrill — North American Cephalopods. 



istence of large chromatophores on the inner surface of the arms, 

 between the suckers, is also a good diagnostic mark, by which to dis- 

 tinguish it from our species of Rossia^ which hav^e the corresponding 

 parts nearly white, or with few and small chromatophores. 



He.teroteuthis tenera. — Specimens examined. 



Order II.— OCTOPODA Leach. 

 Cephalopoda octopioda Leach, Zool. Miscel., iii, 1817 (t. Gray). 



Ferussac Tableau Syst., p. 18, 1821. 



D'Orbigoy, Tab. Method., p. 45, 1825; D'Orbigny, Cephal. Acetab., p. 1. 

 Octocera Blainv., Diet. Sci. Nat., voL xxxii, 1824. 

 Octopia Gray, Cat. Moll. Brit. Mus., i, p. 3, 1849. 



Anns eight, similar, all furnished with suckers in one or two rows ; 

 often more or less united by a web, without natatory crests. Suck- 

 ers sessile, not oblique, destitute of horny rings or hooks. No 

 tentacular arms. Head often larger than the body. Body short and 



