240 " ENDEAVOUR "' SCIENTIFIC RESULTS. 



believe it to be probable from McCoy's description that he^ 

 himself, observed the peculiar double hectocotylus, as he 

 speaks (1888, p. 256) of " the replacement of the suckers by 

 tubercles on bases of two of the arms in some specimens," 

 inferring this to be " accidental," but from the context it is 

 perhaps not quite apparent whether he was here referring 

 to his own species or to Gould's description of the related 

 0. insignis, much misunderstood initil its recent elucidation 

 by Pfefier. How so elaborately developed an organ as the 

 hectocotylized arm in this species could possibly be construed 

 as " accidental " is a bit difficult to understand, although it 

 should be remembered that in McCoy's time, except for the 

 brief observations of Gould, nothing resembling it had been 

 described in the entire class Cephalopoda. Even now I am 

 aware of no other oegopsid which boasts a hectocotylus of such 

 complexity. Without actual observation of the animal in 

 life, it would indeed be hazardous to speculate on the func- 

 tions of its innumerable special modifications, but one is 

 quickly struck mth the notion that the hard, massive, jagged, 

 in-facing tubercles so powerfully developed on the basal 

 segments of both ventral arms (PI. Ixv., fig. 2) might well 

 co-operate to form a most efficient clasping organ. 



0. gouldi has not been reidentified with any certainty since 

 its original description and consequently has never been 

 properly understood or received general acceptance, despite 

 the fact that, though somewhat stereotyped, McCoy's 

 description and figures are really very good. The principal 

 points wherein the present specimens fail to accord with his 

 diagnosis are all to be explained, it seems to me, on the basis 

 either of incomplete representation (as in the lack of a foveola 

 in McCoy's drawing, the small number of grooves in the 

 cone of the gladius, and the lack of interstitial teeth or plates 

 in the tentacular horny rings), or as being within the limits of 

 normal variation (as where the number of teeth in the 

 marginal tentacular suckers is given as 20). McCoy also 

 mentions that the arms in his specimen, except on the ventral 

 margins of the third pair, are " without membranous borders." 

 In the " Endeavour " material the ventral membranes of the 

 third arms are simply a trifle wider than elsewhere. 



Pfeffer, in his great monograph (1912, p. 459*), describes the 



*Pfeffer's description in full is as follows : — 



" Das vorliegende Stuck des Gottinger Museums von 170 mm. Mantel- 

 lange hat einen hektokotylisierten rechten Ventralarm. Die proximale Halfte 

 desArmes ist durchaus normal gebildet; die distale Halfte ist stark umgebildet, 

 und zwar in einer Weise, die sich von der Hektokotvlisation des verwandten 

 0. sagittatus betrachtlich unterscheidet. Betrachten Avir zunachst die 



