43 



lines in length : they were principally attached along the line of the exterior 

 elevated ridge, at which part the nutrient vessels penetrated the ovary. 



The oviduct (e. /. fig. 9. pi. 8.) was not an immediate continuation of the ovary 

 as in the Dibranchiata , but commenced, like that of the oviparous Vertebrata, 

 by an aperture distinct from the gland. This aperture was of a semilunar 

 form, and was situated directly above the orifice of the ovary in the peritoneal 

 membrane which connects that gland to the pericardium. The oviduct was a 

 flattened tube of about an inch in length, and from four to five lines in breadth ; 

 it extended forward by the side of the intestine, (without dividing as in Ocythoe 

 and Octopus,) and terminated at the base of the funnel close to the anus. It 

 became enlarged towards the extremity, and was deeply furrowed in the trans- 

 verse direction both within and without ; the parietes were also here thick and 

 puljiy, and apparently glandular. It is probable, however, that the ova derive 

 an additional exterior covering and connecting substance from the secretion of a 

 large glandular apparatus (fig. 10. pi. 8.) which is situated immediately below 

 the terminal orifice of the oviduct ; and which, as no other use is obvious, I shall 

 here describe in connexion with the genital system. This apparatus is attached 

 to the mantle, and gives rise to the two rounded convexities observable on the 

 ventral aspect of the body behind the funnel. It is a transversely oblong mass, 

 composed of numerous close-set pectinated membranous laminae, which are 

 about a quarter of an inch in depth, and are disposed in three groups : those of 

 the larger group extend transversely across the mesial line of the body, and are 

 unprotected by a membrane ; but the two smaller divisions are symmetrically 

 disposed, and have the unattached edges of the laminse covered by a thin mem- 

 brane, which is reflected over them from the anterior margin of the glandular 

 body. These divisions form the sides and anterior part of the gland ; and as 

 the secreted matter must pass backwards to escape from beneath the margin of 

 the protecting membrane, this membrane may serve both to conduct the secretion 

 nearer the orifice of the oviduct, and also to prevent its being drawn within the 

 respiratory currents of water, and so washed away as soon as formed. With 

 the exception of this distinct glandular apparatus, the generative system of the 

 Pearly Nautilus, as exhibited in this female, differs very little from that of the 

 higher Cephalopods. 



G z 



