H. B. Kirx.—On the Anatomy of Sepioteuthis bilineata. 147 
Funnel (pls. ii 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 (pl. viii, fig. 15i), 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 (pls. iii., 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 8-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 (pl. 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 
