578 



In the communication published in April I remarked upon the 

 improbability of Rabl-Riickhard's suggestion (Zool. Anzeiger 1881, 

 p. 281) that a commissure in the roof of the ventriculus communis in 

 the Reptilian brain represents the fornix. His hypothesis proves to be 

 untenable on several grounds ^. The brain of Tropidonoüis has a very 

 large anterior commissure and a distinct but feebly developed corpus 

 callosum. In transverse sections, through the terminal plate, we obr 

 serve the pars olfactoria below, then the pars temporalis and at some 

 distance above this, the corpus callosum. At either side of the corpus 

 callosum are distinct vertical tracts which pass above into the callosal 

 bundle and probably unite with the commissura cornu ammonis. 

 Below, they descend behind the anterior commissure. These tracts 

 probably represent the columns of the fornix. This conclusion is 

 founded upon the close resemblance between the relations of the fibre 

 tracts above described and those observed in the embryo mammalian 

 brain. I hope soon to procure more complete sections which will 

 enable me to confirm this interesting observation. 

 August, 27th 1886. 



2 Morphol. Jahrbuch 12. Bd. p. 250. 



III. Mittheilungen aus Museen, Instituten etc. 



1. Linnean Society of New South Wales. 



30*^ June, 1886. — 1) Note on Ctenodax Wilkinsoni. By William 

 Macie ay, F.L.S., etc. It is here explained that the fish described by Mr. 

 Macleay under the above name has been ascertained by Dr. Ramsay of the 

 Australian Museum to be closely allied to Tetragonurus Cuvieri of Risso. 

 Some remarks are also made on the habits and affinities of the fish. — 

 2) Geological. — 3) Notes on Australian Earthworms. Part I. By J. J. 

 Fletcher, M.A., B.Sc. Up to the present time but three Australian Earth- 

 worms have been described, Lumbricus Novce-Hollandiœ, Kinberg, and Di- 

 gaster lumbricoides, Perrier, from N. S.W., and Megascolides aiistralis, McCoy, 

 from Victoria. In this paper a fuller account is given of Kinberg's species, 

 and descriptions are given of six new or undescribed worms from the rich 

 volcanic soil of Burrawang and of Mt. Wilson. Of these, two species [P. 

 Coxii and P. australis] are referred to Schmarda's genus Perichœta ; two 

 others [N. Camdenensis and N. grandis] are included in a new intraclitellian 

 genus Notoscolex\ a fifth [Didymogaster silvaticus) also is intraclitellian but 

 difi"ers îrom Noioscokx ; and the sixth [Cryptodrikis] is postclitellian, with eight 

 rows of setae , but is difierent from Digaster. Three of these, as far as is 

 known at present, occur only at Burrawang, one at Mt. Wilson only, one 

 is common to both localities as well as Sydney, and one occurs at Burrawang, 

 Springwood and Jervis Bay. Mr. Fletcher has heard of the occurrence of 

 worms, some of them very large, in the Hunter and Manning River districts, 

 and probably these, as well as Illawarra, the Richmond and Clarence districts 



