360 



A. E. Verrill — North American Cephalopods. 



istence of large ehromatophoi'es on the inner surface of the ai'ms, 

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

 tinguish it from our species of Hossia, which have the corresponding 

 parts nearly white, or with few and small chromatophores. 



Order II.— OCTOPODA Leach. 

 Cephalopoda octopoda Leach, Zool. Miscel., hi, 1817 (t. Gray). 

 Ferussac Tableau Syst., p. 18, 1821. 



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

 Octocera Blaiav., Diet. Sci. Nat., vol. xxxii, 1824. 

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



Arms 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 



