CEPHALOPODA OF THE HAWAIIAN ISLANDS. 

 Specimens op Polypus 7- Examined. 



303 



Remarks. — These specimens are obviously not the young of either Polypus ornatus or P. hoylei. 

 In some respects they approach P. marmoratus, but differ decidedly in coloration, in shape, the absence 

 of ocular markings, and the double row of small chromatophores on the ventral arms of the very young. 

 The funnel organ also appears to be a little different, being narrower and more deeply cleft in the 

 median line. Were it not for the papillated surface and the cirri over the eyes, a relationship with 

 P. hawaiiensis might be suggested, but even here these are not the only difficulties. The most con- 

 spicuous features of possibly diagnostic importance in addition to those just noted are the short dorsal 

 arms, the subequal dimensions of the remainder, the elongate body, and the relative shortness of the 

 umbrella dorsally. Some of the specimens have a superficial resemblance to Scaeurgus patagiatus in 

 a general way, but of course lack the marginal fold and other distinguishing features. As in the latter 

 species, the body is remarkable for its compactness and solid consistency in alcohol. 



Polypus 3 (young). 



A single badly mutilated Polypus taken on the reef at Honolulu by Dr. O. P. Jenkins and now in 

 the Stanford University collections does not seem clearly identifiable with any of the other forms which 

 have been discussed. It is chiefly characterized by its small ovoid body, smooth save for a few small 

 isolated papilla; broad head; protruding eyes, ornamented above by two or three minute cirri; the 

 very scanty umbrella, which is much shorter than in any other Hawaiian Polypus, not even 

 excepting P. ornatus; short dorsal arms, and the extremely stout and long arms of the third and fourth 

 pairs. The arms of the second pair are both mutilated, but with this exception the order of relative 

 length is 3=4.1. The suckers are fairly large, very numerous, and close set. The color is cloudy black 

 above, pale beneath. 



In some respects this specimen recalls P. ornatus, but in most ways the aspect is notably different. 

 It is No. 186 of the author's register. 



Measurements op Polypus S. 



Total length 162 



Tip of body to base of dorsal arms 22 



Length of body 15 



Width of body 14 



Width of neck 10 



Width of head 12 



Length of— 



Right dorsal arm 17+ 



Left dorsal arm 71 



Right second arm 17+ 



Length of— mm. 



Left second arm 32+ 



Right third arm 37+ 



Left third arm 137 



Right ventral arm 133 



Left ventral arm 140 



Umbrella between dorsal arms 5 



Umbrella between ventral arms 9 



Diameter of largest suckers 3 



Diameter of mantle opening g. 5 



Length of funnel g 



