,1889.] ANATOxMY OF GONATUS FABRICII. 127 



the posterior end I regret my inability to give a satisfactory account 

 of its distribution, and the more so since it would have been interesting 

 to ascertain how far it agrees with what Brock ^ has indicated as the 

 tyjiical arrangement among the CEgopsida. All that I am able to 

 assert is that this vessel does not branch until a distance of about 

 2 centim. from the heart ; at which ])oint it bifurcates. It seems 

 probable that these two branches represent the anterior and posterior 

 aortae of Brock, in which case I have failed to discover the arteria 

 genitahs ; this, however, is not much to be wondered at considering 

 the state of preservation of the specimens. There were no aortic 

 hearts to be seen in any of these vessels. 



The Fena Cava (v.c.) bifurcates on a level with the anterior part 

 of the ventricle ; a branch passing to each branchial heart, at 

 the entrance to which it is joined by a vein passing from behind 

 forwards over the dorsal surface of the branchial heart (p.v.c). 

 A third vein (o.v.), beset like the others with renal sacculi, 

 passes over the dorsal surface of the left brancliial heart and then 

 turns downwards over the root of the left gill to join the other 

 vessels entering the left branchial heart ; it probably comes from the 

 ovary, but it was impossible to make this out with certainty. 



The right branchial heart {br.h.") is somewhat smaller and 

 more distinctly quadrate in form than the left (br.h.'). Each of 

 them bears upon its dorsal anterior margin a small flattened sphe- 

 roidal pericardial gland {p.gl.). 



IX. Respiratory Organs. 



The Gills appear, on the whole, to be constructed on the same 

 type as in Ommastrephes ', as was noticed by Verrill. 



X. Excretory and Generative Organs. 



Regarding the Renal Organs nothing more of any importance was 

 made out than has been noted above (p. 119). 



But little can be said regarding the generative organs. The two 

 larger specimens which I examined were both females, as was shown 

 by the presence of the oviducts (Plate XIII. fig. 3, od.). There 

 are two of these, which are gently curved and pass forwards 

 just external to, and on the dorsal surface of, the root of each gill. 

 Their extremities are pointed and the opening is a slit on one side of 

 the tip. 



Nidamental glands are present as two flattened sausage-shaped 

 bodies, with their convexities directed towards each other, in the 

 middle line. They present the usual lamellar structure. 



Regarding the male organs Verrill makes the following state- 

 ments : — " The specimen is still immature, and probably only one 

 year old. The spermary or 'testicle' is small (length 18™", 

 diameters 2"" and 4"°'), flattened, tapering backward, partly 



1 Op. cit. p. 247. 



^ Joubin, " Struct, et devel. de la Branchie des Ceph.," Arch. Zool. exp. (2) 

 iii. 1885. 



