374> Zoological Society. 



Mr. Owen mentioned as an additional instance of the existence 

 of this power in the Loligo sagittata, that two specimens were pre- 

 served in the Museum of the Royal College of Surgeons, to which 

 they were presented by Dr. Henderson as having leaped on board a 

 vessel in the Mediterranean. 



Dr. Grant again called the attention of the Society to his spe- 

 cimen of Loligopsis guttata, Grant, and to specimens of Sepiola vul- 

 garis, Leach, for the purpose of explaining more fully the anatomical 

 structure of these species, which he had exhibited, with Sepiola steno- 

 dactyla, Grant, at the Meetings on February 12 and March 26. He 

 gave a detailed account of their anatomy, which he illustrated by 

 reference to an extensive series of diagrams prepared by himself. 

 These diagrams have been engraved on a reduced scale for publi- 

 cation in the Society's Transactions. 



In the Loligopsis the parietes of the mantle are remarkably thin 

 and loose, excepting where they are supported by the dorsal trans- 

 parent lamina, and by two thin cartilaginous laminae extending from 

 the free edge of the mantle about half-way down the sides, and 

 placed rather towards the ventral surface of the animal. These la- 

 teral laminae present an appearance anomalous in Cephalopods. Each 

 of them sends out twelve or thirteen conical tubercles, about a line 

 in diameter at their base, and projecting to the distance of a line 

 beyond the general surface of the mantle. 



The viscera occupy but a small portion of the cavity of the mantle, 

 in which they are placed far backwards, the branchiae themselves not 

 extending forwards beyond the middle of the sac. The liver is di- 

 vided, as in Nautilus, into four principal lobes, which are quite se- 

 parate from each other- but the lobules which compose these lobes 

 are not, as in the Testaceous Cephalopod, detached from each other. 

 The branchial arteries are surrounded, before entering the auricles, 

 by a spherical cluster of vesicles, like those which open into these 

 vessels in Nautilus ; but the auricles are not, as in Nautilus, wanting: 

 they are, however, destitute of those singular appendices usually 

 found attached to these muscular sacs in the Naked Cephalopods. 

 The branchice are single on each side, and are proportionally the 

 smallest which Dr. Grant has yet met with. The systemic ventricle 

 is very muscular, and of a lengthened fusiform shape : it has an 

 aortal trunk at each end. On the large dorsal or descending aorta 

 there is, as in Nautilus, a distinct bulbous enlargement, probably 

 the commencement of a bulbus arteriosus. 



In Sepiola, in addition to the usual dorsal lamina, which is thin 

 and short, there exist, external to the mantle and supporting the 

 fins, two firm crescentic cartilaginous plates, like scapulae, playing 

 freely on the outer surface of the mantle, and furnished with an outer 

 and an inner layer of muscles, passing in the form of minute white 

 fasciculi, from the middle of the dorsal part of the mantle : by this 

 structure, great extent and effect are given to the motions of these 

 powerful dorsal arms, which have thus a singular resemblance in 

 their mode of attachment to the anterior extremities of Vertebrata. 



The cavity of the mantle is comparatively small, and its whole 

 extent is occupied by the viscera, which are largely developed, par- 



