320 Proceedings of the Royal Physical Society. 



stance of the arm as scarcely to rise above its surface. 

 Their numbers on the different arms are — 



1st. .... 

 2(1 



3d. . . . • . 



4th. .... 



The second arm on the left side has been mutilated, whence 

 its shortness and correspondingly small number of suckers. 

 The third arm on the right side is hectocotylised (PL VI., 

 Fig. 3) ; the interbrachial membrane is produced along its 

 posterior margin in the form of a narrow rounded fillet. 

 Beyond the last sucker the arm is rounded and conical for 

 about 0'5 cm., while the extreme end is moulded into a small 

 spoon-shaped apparatus 0'25 cm. in length; the central por- 

 tion is smooth, flat, and surrounded by a slightly raised margin. 



The Colour (after long preservation in alcohol) is whitish-grey, 

 with brownish-black patches so well pronounced and definite 

 in form, that one is forced to believe they are permanent and 

 distinct from those changes in colour for which these animals 

 are so remarkable.* On the upper surface and sides of the 

 body are (20-25) oval annular patches about 2 mm. in length 

 by 1-1"5 mm. in breadth; the ring presenting a dull grey 

 semi-transparent appearance, while around and in the centre 

 of it a lens reveals minute brown dots (chromatophores), 

 which become less numerous as one recedes from the ring. 

 At a little distance the effect produced is that of a large 

 oval patch with a black centre, and gradually shading away 

 towards its margins. Similar spots occur on the upper sur- 

 face of the head and on the external and lateral surfaces of 

 the arms, as well as on the outside of the interbrachial 

 membrane. On the arms they form transverse bands, of 

 which there are ten on the longest ; the bands being for the 

 most part rather more than half as wide as the light-coloured 

 spaces which separate them. 



The Mandibles present no noteworthy peculiarities. 



The Radula (PI. VI., Fig. 4) consists of seven series of 

 teeth. The middle tooth of each row, when freshly de- 



* The speciniciKs in the Liverpool Museum show the same distribution of 

 colours. 



