100 



THE VOYAGE OF H.M.S. CHALLENGER. 



Octo-pus punctatus, Gabb (PI. V.). 



1862. Octopus piindatus, Gabb, Proc. Calif. Acad., vol. ii. p. 170. 

 1866. „ „ Dal], Ihicl, vol. iii. p. 243, fig. 27. 



1883. „ . „ Vll., "Blake," Suppl., p. 117, pis. iv., v., fig. 2. 



1885. „ honrjlcongensis, Hoyle, Diagnoses I., p. 224. 



1885. „ „ Hoyle, Prelim. Eep, I., p. 99. 



Habitat. — Station 232, tlie Hyalonema-grouxidi, off Ino Sima Island, Japan, May 12, 

 1875 ; lat. 35° 11' K, long. 139° 28' E.; 345 fatboms ; green mud. One sj)ecimen, J . 



Pacific Coast, San Francisco to Sitka, Alaska (Verrill); Hong Kong (Copenhagen 

 Museum). 



This species was identified in the summer of 1884 by comparison with four specimens 

 which had been named by Steenstrup, Octopus hongkongensis, and although the 

 Challenger example greatly exceeded them in size, it nevertheless agreed with them so 

 remarkably in the form of the minute pimples on the body and in the shape and 

 proportions of the hectocotylised arm, that there could be no doubt they all belonged 

 to the same species. Since that time Professor Verrill has kindly sent me a copy of 

 his descriptions of two species of Octopus from California {op. cit.), and a comparison 

 of his account of Octopus punctatus, with the Challenger specimen irom Japan, has 

 convinced me that they must all be referred to one type, which will of course bear the 

 name selected by Gabb. 



A large sucker, some 30 mm. or more in diameter, in the British Museum, seems to 

 me almost certainly to have belonged to an individual of this species. 



I append the dimensions of the Challenger specimen for comparison with those given 

 by Verrill ; the length of the arms seems to be very variable. 



Dimensions. 



Length, total. 



End of body to mantle-margin. 



End of body to eye, 



Breadth of body, . 



Breadth of bead, . 



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. 



Length of first arm, .... 



Length of second arm, .... 



Length of third arm, . . . ■ 



Length of fourth arm, .... 



650 mm, 



70 



90 



90 



65 

 130 

 150 



31 

 4 



11 



Eight. 



Left. 



510 mm. 



530 mm 



520 „ 



500 „ 



290 „ 



440 „ 



355 „ 1 



410 „ 



1 The estremity is missing 



