Dr. C. W. Andrews — Notes on Egyptian Eocene Mammals. 157 



student follow the zigzag and tortuous nomenclature of the Ammon- 

 ites, as he views them to-day by the light of modei'n writers on this 

 group ? Or, to take a less perplexing branch, the British non-marine 

 Mollusca (as recorded by B. B. Woodward, 1903). What becomes 

 of our knowledge, derived from the past, if out of 167 names defined 

 by Forbes and Hanley, only 51 remain intact ? Such metamorphoses 

 are too startling. 



One pressing matter remains to be mentioned, that is, a General 

 Index to the forty annual volumes of the Geological Magazine. 



The Index is 2Jrepared in MS. by Mrs. Woodward. The question 

 is, shall it be printed ? If, say, 300 of our readers are prepared to 

 subscribe one guinea each for a copy, this work of reference might 

 be published. It would unquestionably prove of the greatest value 

 to all workers in geology and palaeontology. 



Every year Time strikes off some name from our list of old and 

 valued friends, and each year gives us some new ones to add, but we 

 crave more subscribers in order to be able to give more illustrations 

 and so add new interest to our journal. In conclusion, we trust 

 that the fifth decade may be brighter and more successful than 

 the four already completed, for our readers and subscribers as 

 well as for our kind-hearted and always encouraging and helpful 

 friend the Publisher, and lastly for ourselves that we may be 

 permitted to witness the Jubilteum of the Geological Magazine. 



H. W. 



II. — FuETHEK Notes on the Mabimals op the Eocene of Egypt, 



By C. ^Y. Andrews, D.Sc, F.G.S., British Museum (Xatural History). 



Part II. 



(PLATE VI.) 



Arsinoitherium. 



THE shuU of one species (A. Zitteli) of this remarkable ungulate 

 has already been figured by Mr. Beadnell, and also in thi& 

 Magazine (December, 1903), where its general form is well shown. 

 Details of the structure of the skull and skeleton will be given in 

 the monograph, so that only a few of the more important characters 

 need be referred to here. 



The pedunculate occipital condyles are very large and prominent ; 

 the occipital surface slopes strongly forwards and is bordered by 

 a massive lambdoidal ridge, which on either side (in old animals at 

 least) rises into a prominent backwardly directed boss of bone, 

 almost like a blunt horn. The parietal region of the cranial roof 

 is flat and is at right angles to the side walls of the skull, being 

 sharply marked off from them by well-defined ridges, which form 

 the upper limits of the temporal fossas. The suture between the 

 parietals is obliterated in the youngest skull examined. The pair 

 of small posterior horns over the orbits are borne exclusively by 

 the frontals, while the great anterior pair seem to be formed entirely 

 by the enormously developed nasals. 



The squamosal takes a large share in the formation of the side 



