[185] CEPHALOPODS OF NORTHEASTERN COAST OF AMERICA. 395 



OCTOPUS Lamarck, 1799. 



Octopus (j)ars) Lamarck, Syst. des Aniru. saris Vert., p. 60, 1801. Cuvier, Reg. Auim. ii. 

 1817. D'Orbigny, Cc'phal. Acdtab., p. 3. Gray, Catal. Moll. Brit. Mus.,i, p. 4, 

 1849. Verrill, Trans. Conn. Acad., v, p. 307, 1881. 



Body short, thick, more or less rounded, usually flattened, often 

 tubercular or warty, but sometimes smooth, usually with one or more 

 tubercles or cirri situated above the eye. Mantle directly united to the 

 head, dorsally, by a broad commissure, extending below the eyes to the 

 base of the siphon. Base of the siphon without any complicated, con- 

 nective cartilages. Arms united by a more or less extensive basal web. 

 Suckers sessile, in two alternating rows. Siphon not intimately united 

 to the whole length of the head, the free terminal portion situated be- 

 hind or beneath the eyes. No aquiferous pores nor brachial pouches. 



The sexes are similar in form. In the male the right arm of the third 

 pair is hectocotylized, its terminal portion being changed into a spoon- 

 shaped organ, smooth on the outer, convex side and furnished with a 

 series of transverse ridges on the inner concave side, and with a basal 

 angular lobe, from which a groove or furrow extends along the lower 

 margin of the arm to the basal web. In some species of Octojrus the 

 modified tip is very small, but in others, very large. 



The female has the oviducts symmetrically developed on both sides. 

 The egg-sacs are large, pyriform, not very numerous, attached by the 

 small end. 



Octopus Bairdii Verrill. — Baird's devil-fish. 



Octopus Bairdii Verrill, Amer. Journ. Sci., v, p. 5, Jan., 1873 ; xix,p. 294, 1830; 



American Naturalist, vii, p. 394, figs. 76,77, 1873; Am. Assoc. Adv. Sci. 



for 1873, p. 348, pi. 1, figs. 1, 2, 1874. 

 G. 0. Sars, Mollusca Regionis Arcticse Norvegiae, p. 339, pi. 33, figs. 1-10 ( 9 ) ; 



pi. xvii, figs. 8a to 8d (dentition and jaws), 1878. 

 Tryon, Man. Conch., i, p. 116, pi. 32, figs. 37, 38 (description and figures from 



the papers by A. E. V.). 

 Verrill, Trans. Conn. Acad., v, p. 368, pi. 33, figs. 1, la ; pi. 34, figs. 5, 6 ; pi. 36, 



fig. 10 ; pi. 38, fig. 8 ; pi. 49, figs. 4, 4a ; pi. 51, figs. 1, la; Bulletin Mus. Comp. 



Zool.,viii,p. 107, pi. 2, figs. 4, 4a; pi. 4, figs. 1, la, 1881. 



Plate XLI, figures 1, 2, 3, 3a. Plate XLII, figures 1-5. 



The body is short, thick, somewhat depressed, broadly rounded pos- 

 teriorly, separated from the head only by a slight constriction at the 

 sides. Head almost as broad as the body, swollen above and around 

 the eyes, concave in the middle above; around the eyes, and especially 

 in front and above, there are numerous small, conical, often irregular 

 and rough tubercles ; a little removed from the upper side of each eye 

 is a much larger, rough, irregularly conical, erectile cirrus, which has 

 some small, more or less prominent, conical papilla? on its surface; the 

 whole upper surface of the body, head, and arms is also covered with 

 minute scattered papilla?, which are usually but little prominent, but in 

 some of the larger males they become much larger and more numerous, 

 and have the form of small prominent warts. 



