EUMENIS. 



directed towards the oesophagus ; each row contains about twelve spines. The character of 

 the central portion was not ascertained. 



The oesophagus passes from the posterior extremity of the buccal mass, and is a narrow 

 tube of no great extent ; the configuration of the stomach was not precisely determined ; 

 the intestine terminates at the anal aperture on the right side of the body, about half way 

 between the head and tail. The upper portion of the stomach appears to be granular, and 

 from each side of it arise two tubes. The anterior one passes forwards and gives off branches 

 to the branchial membrane of the sides of the head, which terminate in the papillae in the 

 form of blind sacs ; the posterior tube, sloping a little backwards, penetrates in the same 

 manner the succeeding portion of the branchiae. The great central canal of the hepatic organ 

 lies below the ovary, as in Dendronotus, and, as in that genus, it is thick and glandular 

 throughout, and is much folliculated. From the sides of this portion three or four branches 

 are given off in pairs, penetrating to the branchiae, as in the rest of the Eolididae. At first 

 these branches are thick, but on reaching the skin they attenuate and ramify over it in a 

 radiating or dendritic manner. All the branches are glandular and folliculated. 



The generative organs, as far as we have been able to trace them, resemble those of 

 Eolis ; the same extensive ovary, composed of lateral lobes, fills almost entirely the posterior 

 portion of the body ; the mucous gland, attached to the female parts, is also largely developed, 

 and extends across the anterior cavity of the body, and the testis is a convoluted tube, lying 

 in front, at the right side, immediately behind the tentacle. 



The cerebral ganglions are four in number, and are nearly of equal size. The central 

 pair are of a sub-triangular form, and are not placed in contact, side by side, as in Eolis, but 

 are united across the median line by a short and stout, though distinct commissure : the 

 lateral pair are attached to the under side of the central ganglions, and are elliptical in 

 form : they are united beneath the oesophagus by a short, stout collar. The buccal ganglions 

 are small and oval, with the collar that joins them to the cerebral ganglions more constricted 

 than in Eolis. The nerves, nine pairs of which were made out, radiate from these centres 

 in the usual manner. Ganglions were also observed at the base of the tentacles. 



EXPLANATION OF THE FIGURES. 



Fig. 8. General view of the viscera of Eumenis marmorata, the dorsal skin being laid open and turned 

 back, and the heart removed : — a, buccal mass ; b, oesophagus ; c, stomach ; d, d, d, d } 

 branches passing from the stomach to the anterior branchial lobes ; e, intestine ;* /, central 

 mass, or folliculated channel of the liver ; g, g, g, g, branches from the central channel going 

 to the skin and branchial papillse ; h, testis ; i, great mucous gland belonging to the female 

 parts ; j, ovary, with the posterior portion removed to show the hepatic organ beneath ; k, 

 cerebral ganglions. 

 9. Lateral view of the buccal mass : — a, oesophagus ; b, channel of the mouth ; c, corneous jaws, 

 imbedded in the muscles. 



10. Internal view of a corneous plate. 



11. External view of the same. 



12. Spines, or teeth, from the tongue. 



13. Cerebral ganglions: — a } a, central pair; b, b, lateral pair; c, buccal pair. 



* The intestine, oesophagus, and stomach were imperfectly made out. The delineation of these 

 organs, therefore, is in part from conjecture. 



