86 



THE VOYAGE OF H.M.S. CHALLENGER. 



Dimensions. 

 Length, total, 



End of body to mantle-margin, 

 End of body to eye, 

 Breadth of body, 

 Breadth of head, 



Eye to edge of umbrella (dorsally). 

 Eye to edge of umbrella (laterally). 

 Length of extremity of hectocotylised arm, 

 Breadth of extremity of hectocotylised arm. 

 Diameter of largest sucker on lateral arm. 

 Diameter of largest sucker on ventral arm. 



Length of first arm,^ . 

 Length of second arm. 

 Length of third arm, . 

 Length of fourth arm. 



Right. 



Left. 



530 mm. 



490 mm 



560 „ 



400 „ 



470 „ 



540 „ 



560 „ 



510 „ 



? 





<^ 





630 mm. 



580 mm. 



70 , 





80 , 





95 , 





105 , 





70 , 





70 , 





43 , 





50 , 





75 , 





75 , 





100 , 





105 , 

 2 

 1 , 





7 , 



' 



14 , 

 10 , 









$ 





Ri 



ght. Left. 





460 



mm. 315 2 mm. 





400 



„ 500 „ 





315 



., 475 „ 





400 



„ 470 „ 



This species presents in some respects a resemblance to Octopus himaculatus,^ Verrill, 

 namely, in the general form and proportions, in the enlargement of one or more suckers 

 on the lateral arms and in the small size of the hectocotylus of the male, as also in the 

 presence of the dark spot on either side in front of the eye. Each, too, has a supra-ocular 

 cirrus, but the conspicuously warted upper surface of Verrill's form and the equally 

 marked smoothness of the Challenger specimens, as well as the seemingly constant differ- 

 ence of coloration necessitate their separation. 



Octopus bimaculatus is from California, so that so far as regards habitat there would 

 be no d pnori ground for separating the two forms. 



The new species agrees with unnamed specimens, from the same locality, in the 

 Copenhagen Museum, in which the spots upon the side of the membrane are even more 

 clearly marked, while the other characters remain the same. 



It approaches Octopus ha-waiensis, E. and S.,* in general form, but differs in the 

 presence of cirri over the eyes. 



Octopus areolatus, de Haan, MS. (PI. III. figs. 6, 7). 



1835. Octopus areolatus, de Haan, MS. letter (fide d'Orbigny). 



1838. „ „ d'Orbigny, Ceph. acet., p. 65. 



1838. ,, sinensis {?), d'Orbigny, C^ph. acet., p. 68; Poulpes, pi. ix.. 



1849. „ ocellatus, Gray, B. M. C, p. 15. 



1886. ,, ,, AppeUbf, Japanaka Ceph., p. 8, pi. i. figs. 1-3. 



Habitat. — Station 192, off the Ki Islands, south of Papua, September 26, 1874 ; 



lat. 5° 49' 15" S., long. 132° 14' 15" E.; 140 fathoms ; blue mud. One specimen, 9. . 



Japan (de Haan, Appellof) ; Hong Kong (Copenhagen Museum). 



1 The lengths of the arms are measured from the eye. ^ Mutilated. 



3 Bull. Mus. Comp. Zoiil., vol. .xi. p. 121, 1883. * Voy. " Bonite," p. 9, pi. i. figs. 1-5. 



