424 MISS DOROTHEA BATE OX 



as a cliarac'ter, move especially when dealing with island foi-ms^ 

 if island form this be. 



One specinien shows veiy distinctly the distal joining of the 

 tibia and tibula which, according to Weber*, is an important 

 character distinguishing the Myomorpha from the Sciuro- 

 niorpha in which these two bones are only joined proximally. 

 Lydekker t, on the other hand, attached little weight to this 

 point, although admitting that a distal union is unknown among 

 living Sciuromorphs. Unfortunately, there is not yet sufficient, 

 material available to settle definitely the question of the syste- 

 matic position of the genus, though the latter author was 

 probablv cori-ect in suggesting that Leithia constituted a separate 

 family, Leithiida?. This view is strengthened by the fact that, 

 two further species of Leithia, not yet described, have been 

 discovered by the writer in the cave-deposits of the Balearic 

 Islands. This greatly extends the known range of the genus, 

 -which is, no doubt, another representative of the " Tyrrhenian "■ 

 fauna preserved in the Pleistocene deposits of the islands of the 

 western Mediterranean region. 



Through the courtesy of Mr. J. Wilfrid Jackson I have been 

 able to examine an imperfect left mandibular ramus of a small 

 species of fox from the Pleistocene of Malta, belonging to the 

 collection of the Manchester Museum. So far as I am aware, no 

 fox is found in the island at the present day, and still further 

 interest is given to this specimen in that this occurrence of a 

 small carnivore for which Leithia would appear to be a suitable 

 prey, suggests that the abundance and tendency towards an 

 increase in size in the rodent can only be explained by the theory 

 that it was at any rate more or less arboreal in habit. That it 

 was not highly specialised for a fossorial mode of life is shown 

 by the shape of the skull and the curvatru'e of the incisors t- 



Equus. — Pinds of Equus-vem&.\\\s in the Pleistocene cave and 

 fissure deposits of Malta have been very few up to the present, 

 and, so far as I am aware, none has been recorded from the other 

 islands of the Mediterranean, though their occurrence in the 

 Genista Cave, Gibraltar, has been noted by Dr. Hugh Falconer 

 in his list of species from that locality §. Further woik in this 

 region will probably yield other finds of a similar kind. 



The present collection includes a left upper pm. 2, which is 

 believed to be that of a small horse, for its crown pattern shows 

 the small enamel-fold described as fold 5 (" pli caballin) " by Prof. 

 H. F. Osboi'u, who considers its presence a means of distinguishing 

 molars of E. cahcdlus from those of E. asinus IJ. It indicates an 

 animal of about the size of a New Forest pony. The greatest 



* ' Die Sausetliiere,' Jena, 1904, p. 489. 



t Proc. Zool. Soc. 1895, p. 862, footnote. 



X I am indebted to Mr. M. A. C. Hiuton for information kindly given me oi> 

 this point. 



§ Pill. Mem. vol. ii. p. 555, London 1868. 



I! Osborn, H. F., "The continuous origin of certain unit characters as observed 

 by a Palaeontologist," Harvey Lectures, Ser. 1911-12, pp. 200-1, tig. 8. 



