H. B. Kirk.— On the Anatomy of Sepioteuthis bilineata. 147 



Funnel (pis. in., iv. a, and viii., fig. 16). — The funnel is large, flat- 

 tened, somewhat conical in shape, longer than broad, and rounded at its 

 apex. On each side of its base is a cartilaginous expansion, presenting a 

 groove to lodge the articular ridges developed on the inner surface of the 

 mantle. Its margins lie loosely upon the funnel. Between the surface of 

 the head and the funnel are muscular bands ; and these are so strongly 

 developed on either side as to form a "cup-shaped cavity at the base of the 

 funnel between it and the head. 



Inside the aperture of the funnel is a strongly-marked infundibular 

 valve (pi. viii., fig. 15 i), so placed that, when depressed, it entirely 

 closes the aperture. Its free portion forms a semi-circular curve; but 

 the lower part is attached by the margins, so that, when the free por- 

 tion closes the aperture, the opening of the funnel leads into a blind 

 cavity. 



Arms (pis. hi., viii., figs. 5-8).— The fourth pair of arms is the longest ; 

 next in length is the third ; next the second ; the first being the shortest 

 and slightest. The arms of the fourth pair are 4-angular in section, and 

 present a slight groove on the peripheral surface, the groove being caused 

 mainly by the great production of the anterior peripheral margin, which is 

 continued below to form the outer wall of the tentacular sac. Those of the 

 third pair are 3-angular, the peripheral surface presenting a sharp angle. 

 The second pair are 3-angular or irregularly 4-angular ; and the first have 

 the peripheral surface rounded, or approach 3-angular. 



The fourth and third arms on each side are connected by a peripheral 

 web, which forms the outer wall of the tentacular sac. This web is attached 

 to the inner peripheral margin of the fourth arm, and to the centre of the 

 peripheral surface of the third arm. It extends to near the tip of the fourth 

 arm, but only a short distance along the third. A very small web connects 

 the third and second arms ; and the second and first have a small web 

 attached at the base to the peripheral surface of each. It extends a 

 very short distance along the second arm, and a still shorter along the 

 first. 



The arms all taper to their extremity. There is a well-marked 

 brachial membrane extending along each side of the acetubular sur- 

 face of the arms and forming a fold, at whose base the suckers are 

 inserted. 



The suckers are arranged in alternate pairs, and this arrangement is 

 observable from the point near the base of the arms at which they first 

 begin to near the tapering extremity, where they become minute tubercles. 

 Each sucker (pi. viii., figs. 10, 11) is sub-spherical or shortly cylindrical in 

 shape, and is borne on a pedicel attached, not to the centre of the base of 



