PEOF. OWEN ON NEW AND EAEE CEPHALOPODA. 149 



In Onychoteuthis banksii the dorsal surface of the head shows a feAv short longitudinal 

 ridges not present in 0. raptor, and the arms shorten in the order 4, 3, 2, 1. The 

 tentacular hooks are also more numerous than in 0. raptor ; and the tentacles them- 

 selves are relatively more slender. 



A mesial longitudinal section of the mantle and some further dissection exposed the 

 following parts (PI. XXIX. fig. 2) :— 



The infundibulum has on each side of its base an elongate narrow cartilaginous 

 cavity, a, which articulates with a prominence of corresponding shape, b, from the inner 

 surface of the opposed side of the mantle. Near the apex of the funnel lay the " valve," c, 

 of a semicircular shape. At the base of the funnel opens the vent, cl ; the anal end of 

 the rectum supports a pair of filamentary appendages, e, e. The duct of the " ink-bag," g, 

 terminates just within the anal verge. At the base of the gills, h, h, are the branchial 

 hearts, ^, ^, each with a small fleshy appendage, k. A portion of the systemic heart is 

 exposed at m. Portions of the "musculi retractores infundibuli" are shown at n. 



The specimen was a female, and probably young. The long narrow ovary, o, not 

 developed as at the sexual period, occupies the narrow pointed fundus of the abdominal 

 cavity. Seemingly single outwardly, its inner capsule forms a mesial septum, indicative 

 of the parial character. From each moiety is continued an oviduct, p, which, after some 

 convolutions, terminates in an enlarged outlet, the thick soft lining membrane of which 

 is disposed in folds radiating from the central aperture, q. The nidamental glands, r, are 

 a pair of elongate bodies situated between the oviductal outlets, beyond which the nar- 

 rower end of the accessory glands extends forward between the branchial hearts. 



The digestive organs being removed, are shown in PL XXIX. fig. 3. A long, slender 

 oesophagus, a, is continued, as in other Decapods, without ingluvial dilatation, to the 

 stomach, h. This is large, oblong, with thinner parietes than in the cancrivorous Octo- 

 pods, but with the muscular fibres radiating from centres on opposite sides of the bag. 

 The pylorus is a slit with tumid borders, and communicates with a second cavity, c, 

 into which open the hepatic ducts, conveying the bile, and also the secretion, probably 

 pancreatic, of the clustered follicles d d, developed upon and from the ducts of the 

 liver. The intestine is continued with a slight bend straight to the tentaculate vent,/. 

 The liver appears to be a single elongated gland with a glistening longitudinally fibrous 

 capsule, g. On removing this a delicate inner layer seemed to form a septum, indicative 

 of a bilobate condition. The cajcal ends of the constituent lobules are shown in the 

 moiety h, from which the fibrous capsule has been removed. The large elongate ink- 

 bag, subbifid at its base, is shown at i ; its duct is short. 



The branchial lamella; are marked a, fig. 4 ; the suspensory ligaments are shown at b ; 

 the systemic veins, with their appended follicles, at c, c ; the branchial hearts and their 

 appendix, at d, d ; the branchial arteries, at e, e ; the branchial veins, oi f,f; the 

 systemic heart, of a rhomboidal or lozenge shape, with its two aortse, ascending and 



descending, is shown at g. 



2b2 



