36 



THE CEPHALOPODA 



277, v.c, p.v, ab.v). Each afferent branchial vessel and the terminal 

 portion of each abdominal vein is enclosed in the cavity of a kidney 

 and is covered externally by an excretory glandular coat (Figs. 273, 

 a.r 277, s.b) Avhich forms the "spongy body" or essential part of 

 kidney (see below). Except in Nautilus, each afferent vessel is 



FK;. 272. 



Ventral view of a male Sepia, obtained by cutting longitudinally the firm mantle-skirt, and 

 drawing the divided halves apart, a, anus ; Br, the single pair of ctenidia ; c, cartilaginous 

 socket in the funnel, to receive c', the cartilaginous knob of the mantle-skirt, the two con- 

 stituting the "pallial hinge apparatus"; C, the head; g, the a/ygos genital papilla and 

 aperture; i, the valve of the fun net; /, the funnel, which has been cut open; m, retractor 

 muscle of the head and funnel ; 1', the fins ; ;-, renal papillae ; R, the glandular tissue of the 

 left kidney, which has been cut open ; t, ink-bag ; r.br, branchial efferent vessel ; v.br", bulbous 

 enlargements (auricles) of the branchial vessels. (From Lankester, after Gegenbaur.) 



expanded at the base of the gill into a contractile glandular swelling 

 known as the " branchial heart," which is also provided with a gland- 

 ular appendage, the homologue of the pericardial gland of other 

 Mollusca (Fig. 277, b.h, a.p). Both branchial heart and appendage 

 are contained in the coelom (Fig. 273, c.v) in the Decapoda, but in 

 the Octopoda only the appendage of the branchial heart is sur- 

 rounded by the pericardial cavity (Fig. 278, ca). In addition to the 



