A. E. Verrlll — North American Cephalopods. 367 



Family OCTOPODID^ D'Oibigny, (restricted). 



Octopotlidce (pars) D'Orbigny, Moll. Viv. et Fos., i, 159, lti4, 1845 (t. Gray); (imrs) 



Cepli;il. Acetab.. p. 3. 

 Odopidm {pars) (Jray. Catal. Moll. Brit. Mas., i, p. 4. 184ft. 



Body slioit, thick, rotinded posteriorly, destitute of lateral fins and 

 internal cartilages. Mantle united to the head by a broad dorsal 

 commissure. Head very large. Connection between the mantle and 

 base of sijjhon simple, without cartilages. Opening to the gill-cavity 

 narrow. Median septum of branchial cavity short, extending for- 

 ward to the base of the siphon, but running back only a short dis- 

 tance. Siphon large, simple. Arms with either one or two rows of 

 suckers, and Avith a more or less developed basal web. No cephalic 

 aquiferous pores. Eyes furnished with an internal translucent lid, and 

 also capable of being covered with the external integument. Sexes 

 similar externally, except that the right arm of the tliird pair in the 

 male is hectocotylized by the formation of a spoon-shaped organ 

 at the tip. 



OCTOPUS Lamarck, 1799. 



Octopus {pars) Lamarck, 8yst. des Auim. sans Vert., p. (50, isoi. 

 Cuvier, Reg. Aniiii., ii, 1817. 

 D'Orbigny, Cephal. Acetab., p. 3. 

 Gray, Catal. Moll. Brit. xMus., i, p. 4, 1849. 



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 compli- 

 cated connective cartilages. Arms united by a more or less extensive 

 basal web. Suckers sessile, in two alternating rows. Siphon not inti- 

 mately united to the whole length of the under side of the head, the 

 free terminal portion situated behind or beneath the eyes. No aquif- 

 erous pores, nor bi'achial pouches. 



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

 third pair is hectocotylized, its terminal ])ortion 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 ansfular lobe from which a groove or furrow extends alontr 

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

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



The female has oviducts on both sides. Eggs comparatively few 



