CEPHALOPODA OF THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 



95 



(fig. 1) on all the eight arms are enlarged for the second quarter of the arm ; after 

 about the first twelve suckers they enlarge very rapidly for about six suckers, and 

 then gradually diminish. The third arm on tlie right side is hectocotylised (fig. 2), 

 and is considerably shorter than its fellow on the opposite side. The seminal groove 

 is well marked, but is neither very broad nor very deep; the modified extremity 



Fig. 3. — Railula <if Polijinis hrurri [H 924]. x 25. 



is unusually long and narrow, and, instead of the usual transverse ridges, siiows a 

 double row of small papillte along its bottom. 



The Surface shows a considerable amount of wrinkling, due apparently to the 

 action of preservative fluids, but was most probably smooth when the animal was 

 alive. There is no trace of any warts or tubercles. 



The Colon)- is dull purplish above, changing gradually into a pinkish stone 

 colour below. 



The liadula is shown in fig. 3. 



Dimensio7is 



End of body to mantle luargm 

 End of body to eye 

 Breadth of body 

 Breadtli of head 

 Eye to edge of umbrella 

 Length of hectocotylus . 

 Breadth of hectocotylus 

 Diameter of largest sucker on arm 



Length of first aim 

 Length of second arm 

 Length of third arm 

 Length of fourth arm 



in Millivietres. 



* jMiitilaterl. 



This species is evidently nearly related to P. megalocyathus (Gould) from the 

 same geographical region. It differs, however, in the absence of the extremely 



(roy. soc. edin. trans., vol. XLVIII., 277.) 



