q/ Nautilus Pompilius. 73 



before him, a parasitic animal form*. Perhaps we may compare 

 with those parts which he describes as fore-stomach and stomach 

 of his Needhamia expulsoria, the parts at the thin extremity of 

 the sperinophore of the Nautilus. After this description, we 

 have from Peters and Milne-Edwardsf, and from DuvernoyJ, 

 indefatigable to the time of his death, excellent and extensive 

 observations on the spermophores in different Cephalopods. 

 Considering that the specimens investigated by us were not 

 recent, a comparison with these observations cannot be of much 

 advantage. Certainly points of correspondence are not wanting, 

 and as far as I can judge from the present state of our know- 

 ledge, the spermophores of Octopus are those which have the 

 closest analogy v/ith the spermophores of Nautilus. The last, 

 however, differ by their extraordinary length from most of the 

 Needhamian bodies that have been hitherto observed, and from 

 all in being rolled up into close convolutions. 



EXPLANATION OF PLATES V. and VL 



Plate V. 



Fig. \. Vertical section of the spadix. In the middle of each of the four 

 tentacles, which make up this organ, is seen at n the section of a 

 nerve that runs longitudinally. The darker tissue, running radially 

 from the margin of the tentacle inwards, consists of longitudinal 

 muscular bundles which have been divided transversely. 



Fig. 2. The male organs of propagation of the Nautilus, from the dorsal 

 surface, their peritoneal sac having been removed : x, x, x, x, the 

 remains of this covering; t, the testis; gl. ace, a second gland 

 of the function of propagation, at the anterior part of which 

 a thin membranous bladder {prostata'? vesicula seminalisl) is 

 enclosed ; from it a canal mounts to the bladder, v. sp. alt., which 

 lies at the right side of the penis, p, and which corresponds to the 

 Needhamian piu-se of other Ce])halopods : from the aperture of 

 the penis at sp., part of a spermophore is passing with the spiral 

 thread which has become free from the bursting of the walls. At 

 p is seen how the penis at this part is continuous with the wall 

 which lies between the gill-sac and the visceral cavity. At f the 

 aperture of the second gland is indicated by which the sperma 

 from the testis is taken up, and above which, within the gland, 

 the inferior extremity of the vas deferens is found. 



Plate VI. 



Fig. I. The penis and the testis of the specimen referred to in p. /O : b, the 

 penis ; sp., spermophore projecting fi-om its aperture ; a, the anus ; 

 e, the large muscle of the shell on the right side of the animal ; 

 k, the anterior, h', the posterior gill of the same side ; g, the 

 mantle reflected. 



* Needhamia expulsoria Sepice officinalis. Beschrieben und abgebildet 

 von Dr. C. G. Cams, Act. Acad. Leop. Carol, vol. xix. P. i. 1839. 

 t By the last-named in Ann. des Sc. Nat. /. c. pp. 331-347. 

 t Mem. de I'Acad. des Sciences, xxiii. 1850. 



