DISTRIBUTKJN. AFFINITIES. 571 



frequently uproot for the purpose of getting at the upper leaves. 



They live to a great age (100 to 120 years, perhaps longer) and 



are said not to attain maturity till the fortieth year. They are 



remarkably intelligent and possess a good memory. The two 



living species are confined to Africa and India (including Ceylon, 



Burma, Malay Peninsula, Sumatra, Cochin China). Both species 



have been domesticated, the African more rarely than the Indian. 



They will rarely breed in captivity. 



The Proboscidea constitute a distinct and on the whole isolated 



order. They are commonly united with the Ungulata. They 



present features of resemblance to the Rodentia (scapula, etc.) 



and Sirenia (succession of teeth, etc.), and in many parts of their 



anatomy are very primitive, e.g. structure of manus and pes, 



presence of two superior venae cavae, uncovered cerebellum, 



abdominal testes. 



The sirenian afl&nities have been recently emphasized by Andrews.* 

 The following characters are common to the two groups : (1) The non- 

 deciduate and zonary placenta, (2) the pectoral mammae, (3) the abdominal 

 testes, (4) the bifid apex of the ventricle, (5) the absence of the condylar 

 foramen always in the Proboscidea and generally in the Sirenia, (6) the 

 bilophodont character of the molars with a tendency to the formation 

 of an additional lobe from the posterior part of the cingulum (talon), 

 (7) the fact that in both groups the molar series move forward in the jaws 

 throughout hfe, the anterior worn teeth being shed, while fresh teeth 

 come into use behind. There is however no evidence of this last character 

 in the earliest Proboscidea, Moeritherium and Palaeomastodon. 



The Proboscidea are first found fossil in the Middle 



Eocene of Egypt and a fairly complete series of forms are known 



connecting the highly specialised modern Elephas with the 



earhest of these remains. Their fossil remains are found in 



both the Old and the New World. 



Elephas L. (Euelephas), i ^ c % p or dm % m % ; the incisors are 

 curved and tipped with enamel ; they are usually larger in the male ; 

 gi-inders with numerous laminae. Fossil species are known from the U. 

 Miocene of India, PHocene and Pleistocene of Evir., Afr., Asia, N. and S. 

 Amer. E. indictis L. (distribution, see above), average dental ridge 

 formula 4, 8, 12, 16, 24, laminae of the worn plates nearly parallel, female 

 without tusks, manus with 5, pes with 4 nails, height of full grown male 

 at the shoulder from 8-11 feet. E. africanus Blumenb. (Loxodon), average 

 ridge formula of molars 3, 6, 7, 7, 8, 10 ; laminae thicker in the middle 

 than at the edges (Fig. 293), manus with 4 nails, pes with 3, tusks in both 

 sexes, but smaller in female ; larger than the Indian species, a full grown 

 male may measure 12 feet to the shoulder. There are many extinct 

 species, of wliich may be mentioned the mammoth E. primigenius Blu- 



* Op, cit. 



