A. E. Verrlll — North American Cephalopods. 381 



Mule : Head as broad as the body, whole upper surface of body 

 and head to base of arms covered with protnineut and jjersistent, un- 

 equal warts, which are roughened by sharp, conical papillte, eight or 

 ten on the larger warts, but only two or three on the smaller ones ; 

 the warts diminish in size anteriorly, and on the sides, before they 

 disappear; around the eyes they form irregular circles ; just above 

 each of the eyes there are two much larger ones, bearing more than 

 twenty conical papilUe ; there is one before and one behind these, of 

 somewhat smaller size. Eyes large, the lower lid purple and thick- 

 ened, overlapping the upper one, which is thin and wliitish. 



Arms considerably longer than the head and body, not very stout, 

 compressed, bearing a single crowded row of large whitish suckers, 

 which are mostly separated by spaces less than half their diameter ; 

 margins of suckers soft and much thickened. The three lower pairs 

 of arms are very nearly equal in length and size ; the dorsal ones are 

 a little shorter and smaller. A thin web unites all the arms for about 

 one-fourth of their length, and runs up along their sides for about 

 half their length. The male has the third right arm (Plate LII, fig. 

 1, la) hectocotylized at the tip ; the modified tip is preceded by forty- 

 five suckers, and is bordered ventrally by a broad membrane, having 

 a white groove along its inner surface ; the terminal organ (fig. \a) 

 consists of a small, ovate-triangular, fleshy disk, with its inner sur- 

 face slightly concave and finely wrinkled transversely, and terminat- 

 ing proximally in a small point. 



Color dark purplish brown, darker purple beneath. Chromato- 

 phorcs small and densely croyvded. 



The female is considerably larger than the male, and has the warts 

 over the back and around the eyes relatively smaller, but of the same 

 character. The arms appear to be larger than those of the male, but 

 this is probably due to the fact that the male has become more con- 

 tracted by the stronger alcohol in which it was placed. 



This female specimen illustrates well the uselessness of the at- 

 tempts to divide the species of Octopus and allied genera into groups 

 or sections, according to the relative length of the arms, as J. E. 

 Gray and others have done, for in this and many other cases the pro- 

 portions of the arms of the right side would throw it into one sec- 

 tion ; those of the left side into another. The male wt)uld have to be 

 put into a third section. 



The two known examples of this species were taken by Mr. A. 

 Agassiz, while dredging on the United States Coast Survey steamer 

 " Blako," in 1880. 



