1889-] ON SCLERORHYNCHUS ATAVUS. 419 



as well as to fray oflF at the sides. Its surface also shows many 

 irregular transverse linear depressions. The apex is broad, obtuse, 

 and fissured, and has been subjected to a certain amount of attrition. 

 A fissure extending almost to the base separates a distinct columnar 

 piece from the anterior and left corner of the principal mass. 

 Although its general structure is obviously that of true horn, it 

 appears to bear the same relation to those in front of it that a nail 

 growing from a diseased or injured matrix does to a normal healthy 

 nail. 



"As the horn of the Rhinoceros is only a greatly modified portion 

 of the animal's skin, specialized for its particular function by the 

 immense development of the papillse of the derm and the exaggerated 

 growth of the epidermic covering, it is not surprising that under 

 some abnormal circumstances, perhaps some local irritation of the 

 skin, a horn should be developed on some other partof the surface from 

 that on which they are usually found. Such an occurrence, however, 

 appears to be rare, and I cannot recall one on record — unless the 

 well-known figure by Albrecht Diirer, copied in so many of the old 

 books on Natural History, of an Indian Rhinoceros with a second 

 born placed between the shoulders, is founded upon fact. The 

 present specimen is certainly interesting as illustrating the method 

 by which such structures as the horn of the Rhinoceros may have 

 been originally developed. 



"A sketch of the animal is given in Sir John C. Willoughby's lately 

 published work on ' East Africa and its Big Game : The Narrative 

 of a Sporting Trip from Zanzibar to the Borders of the Masai.' " 



The Secretary exhibited a skin of an albino variety of the Cape 

 Mole-Rat {Georychus capensis), forwarded to the Society by the 

 Rev. G. H. R. Fisk, C.M.Z.S., of Capetown, and read the following 

 extracts from a letter received from Mr. Fisk on the subject : — 



"I send a skin, prepared for mounting, of a White Mole-Rat, a 

 male. It was given to me alive by Mr. Hiddingh, who so kindly gave 

 me the one which I sent to you some time ago. This one lived for 

 about a week after capture and fed freely, giving no signs of pain ; 

 but, after death, I found that it had been too much hurt by the 

 trap to recover the injury. I put it into the hands of a taxidermist 

 to be properly prepared, thinking that you might like to set it up 

 and place it near the cage of the living animal, so that visitors 

 might gain an idea of the peculiarities of the creature." 



Mr. A. Smith Woodward, F.Z.S., exhibited a fragment of the 

 rostrum of an extinct Saw-fish, Sclerorhynchus atavus, kindly for- 

 warded to him for exainiuation by Prof. Albert Gaudry, and made 

 the fuUowing remarks : — 



" The specimen is shown, of the natural size, in the accompanying 

 drawing (p. 450), and, Hke the type in the British Museum, was 

 obtained from the Upper Cretaceous series of Mount Lebanon. It 

 doubtless pertains to a smaller individual than the last-named fossil 

 and is interesting as showing the extreme slenderness of the rostrum' 



