394 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [184] 



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 XLIV, fig. 3, 3a) hecto- 

 cotylized at the tip ; the modified tip is preceded by 45 suckers, and is 

 bordered ventrally by a broad membrane, having a white groove along 

 its inner surface; the terminal organ (fig. 3a) consists of a small, ovate- 

 triangular, fleshy disk, with its inner surface slightly concave and finely 

 wrinkled transversely, and terminating proximally in a small point. 



Color dark purplish brown, darker purple beneath. Chromatophores 

 small and densely crowded. 



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 useiessness of the attempts 

 to divide the species of Octopus and allied genera into groups or sections 

 according to the relative lengths of the arms, as J. E. Gray and others 

 have done, for in this and many other cases the proportions of the arms 

 of the right side would throw it into one section ; those of the left side 

 into another. The male would have to be put into a third section. 



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



Agassiz, while dredging on the United States Coast Survey steamer 



"Blake," in 1880. 



Measurements in millimeters. 



Total length 



End of body to center of eye 



Breadth of body 



Breadth across eyes 



Length of dorsal arms, from month 



Length of second pair of arms 



Length of third pair of arms 



Length of hectocotylized arm 



Length of modified tip 



Length of ventral arms 



Greatest breadth of lateral arms 



Diameter of largest suckers 



No. 12. 

 Male. 



202 

 58 

 55 

 49 

 135 

 155 



130 



4.5 

 145 

 12 



3 



No. 13. Female. 



Bight side. Left side 



360 

 100 

 65 



255 

 260 

 225 



210 

 18 

 5 



260 

 235 

 240 



225 



18 



5 



