316 NOTE ON A LARGE SQUID. 



below the middle of tlie arm. Along the postero-ventral edge of 

 this arm extends a broad membrane {Lat. memh., Fig. 1)^ about 5 cm. 

 wide near the middle of the arm. This lateral membrane, which is 

 formed by the extension of the platform on which are situated the 

 suckers of the arm, is supported by thick ridges running out from 

 between the suckers. The ventral or fourth pair of sessile arms 

 is 28 cm. long, with a keel but no membrane. 



All the sessile arms have along their inner surface two rows of 

 suckers. One of these is figured (Fig. 2) to show the shape and 

 disposition of the teeth of the horny margin [t, Fig. 2). A fold 

 (/, Fig. 2) supporting horny plates runs round the inner edge. 



The tentacular arms, 64 cm. long, are slender and clubbed. In 

 Fig. 3 I have represented the proximal end of the club of the left 

 tentacle as if cut off, in order to show the slight lateral membrane 

 on the dorsal edge, and the small keel on the outer surface, which 

 is more prominent towards the tip. There are two central rows of 

 suckers [1. c.s., Fig. 3), very large towards the middle of the club, 

 and on each side a row of small long-stalked suckers (s. m. s,, Fig. 3), 

 situated on the transverse ridges which run between the large 

 suckers. In Fig. 2 is shown a large sucker in greater detail ; round 

 the rim internally is a circular shelf-like fold (/., Fig. 2), bearing 

 horny plates. The inner horny margin of the sucker is provided 

 with teeth all round, four of which are large and prominent {t., Fig. 

 2) . At the proximal end of the club on the dorsal edge is the " con- 

 nective apparatus,^^ consisting of three smooth-rimmed suckers (s. r. s.. 

 Fig. 3), alternating with three large tubercles {tub., Fig. 3). The 

 right tentacle bears a corresponding apparatus. The arrangement 

 of these suckers and tubercles is similar to that described and figured 

 by Steenstrup for 0. 'pteroims (2, fig. 2, p. 81 ; and 3, fig. 3). 



From the last suckers on the club to within 15 cm. of the base 

 of the tentacle are fourteen transverse ridges on the inner surface ; 

 they disappear gradually towards the base. Below the buccal 

 membrane, which is provided with seven points, is a cavity com- 

 municating with the exterior by two apertures at the base of the 

 dorsal arms, and two apertures at the base of the tentacles. Outside 

 the base of the tentacles are two pits, or pockets. 



The funnel is represented in Fig. 4 as bent back, so as to expose 

 the pit in which it lies. It is retained by four bridles, two towards 

 the middle line [in. hr., Fig. 4), and a thicker bridle on each side 

 {out. hr., Fig. 4) . Within the bases of attachment of the inner bridles 

 are seen two apertures {d. ap.. Fig. 4), communicating with the 

 cavity of the siphon above the valve."^ Inside the external bridle is 

 an aperture, perhaps artificial, communicating from the siphon pit 



* I have observed these apertures in Thysanoteuthis rhombus. 



