90 



THE VOYAGE OF H.M.S. CHALLEKGEE. 



Octopus duplex, Hoyle (PI. VIL fig. 5). 



1885. Octopus duplex, Hoyle, Diagnoses I., p. 226. 

 1885. „ „ Hoyle, Prelim. Eep. I., p. 101. 



Habitat. — Station 163a, off Twofold Bay,^ South-East Australia, April 4, 1874; 

 lat. 36° 59' S., long. 150° 20' E. ; 150 fathoms; green mud. Two specimens, one $ , 

 one ^ , immature. 



TJie Body is short and evenly rounded, with the merest trace of a median ventral 

 groove. The mantle-opening extends about half round the circumference, and terminates 

 halfway between the siphon and the eye. The siphon is relatively long, conical, and 

 pointed, and extends about halfway to the umbrella-margin. 



The Head is small, and the eyes rather prominent 



ITie Arms seem to have been unequal, the lateral the longest, but so many have been 

 mutilated that it is difficult to be certain ; they are about four times the length of 

 the body. The umbrella extends about one-third up the arms, farthest between the 

 lateral pairs. The suckers are large, close, and prominent, with a narrow margin marked 

 off from the basal portion ; the radial grooves extend to the margin and form notches in 

 it. The hectocotylus is not present, the specimen being a female ; the thii-d right arm 

 has been mutilated, but the stump shows no groove running up the outer ventral margin. 



Tlie Surface is smooth ; an interrupted ridge starting from the base of the siphon 

 passes backwards along the ventro-lateral margin of the body, probably due to contraction. 

 There are three small papillse above each eye. 



The Colour is a pale bluish grey above, shading into a creamy tint below. 



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, . 



Diameter of largest sucker. 



Length of first arm, 

 Length of second arm, 

 Length of third arm. 

 Length of fourth arm, 





15 







17 







18 







13 







13 







2 





Eight. 



Left. 



55 mm. 



53 mm 







53 „ 



(I 



f 



43 



" 



50 „ 



All my efibrts to identify this with any previously known species have failed, which 

 is the more remarkable, inasmuch as it presents no very special distinctive characters. 



1 Hence the specific name." 



