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Show 678 MR. J. GRAHAM KERR ON THE [June 18, ciennes1, and by Lankester2, as a paired structure. Not always, however, does it seem to be so, as in one of the two specimens in which I observed it the laminae were quite continuous across the middle line, the laminae appearing in fact to be mere exaggerations of the fine transverse wrinkles into which the surface of the skin is thrown behind the lamellar organ. Of the two authors referred to, the first, after some hesitation, suggests that the lamellated organ may be tactile in function, " analogous to the palpi round the Crustacean mouth." Lankester, on the other hand, for what reasons is not stated, very definitely describes the organ as " probably olfactorj^."3 During the examination of a mature female somewhat startling evidence was obtained as to the true function of this organ. The lamellae were here covered with a thick coagulated materi apparently secreted by them, spreading over the edges of the lamellae and passing in thin plates down between them. Partially imbedded in the coagulum on the left side and only partially visible, there appeared a peculiar brown structure which at once suggested the appearance of a spermatophore. And upon carefully clearing away the surrounding material the surmise so suggested was corroborated. The long slender spermatophore lay coiled backwards and forwards over the surface of the lamellae in the manner indicated in PI. X X X I X . fig. 2, held firmly in position •by the coagulated material. W e would seem to have here' a peculiar cement-secreting glandular apparatus, on whose sticky surface the spermatophore is deposited by the male. In other Cephalopods the position in which the spermatophore is attached to the female varies: in OZgopsids, Octopods, and Sepiola, e. g., it is passed into the mantle-cavity; in other Decapods (e. g., Sepia, Loliego) it is attached to the skin on the outer surface of the buccal mass. In Nautilus the position is thus a somewhat intermediate one. VIII. The Morphology of the " Arms" of Cephalopods. As Grobben has justly remarked, and as Pelseneer has adopted as text to his paper on the subject, " eine der schwierigsten Fragen in der morphologischen Deutung des Cephalopodenkorpers bildet die Morphologie der Kopfarmen "; and in accordance with this, as well as with its far-reaching interest, the question has attracted from time to time a great amount of attention from morphologists. Eegarding the fundamental nature of these organs, two very different views have been brought forward :- (1) That the arms of Cephalopods are processes of the head or circumoral region. (2) That they are processes of the foot, part of which has grown up on either side so as to finally surround and almost completely hide from view the head itself. 1 Arch. Mus. d'Hist. Nat. torn. ii. p. 277. 2 Zoological Articles, p. 130, a Q^ Ht fig gg_ |