1876.] of the G-reat Indian Desert. 87 



dawn of organized life to the present day, they consist with but few and 

 local exceptions of rocks which have been formed, in all probability, on the 

 surface of the land ; the only case of a marine formation known to exist at 

 a distance of more than 100 miles from the present coast being that of the 

 thin Cretaceous band at Bagh, Barwai, and elsewhere in the western part of 

 the Narbadda valley. On the other side of the great alluvial plain formed 

 by the Indus and Granges all is different. Marine rocks of various ages 

 form the hills of Sind and the Panjab, the greater portion of the Himalay- 

 as and Tibet (so far as the mountains do not consist of metamorphic rocks), 

 the ranges south of the Assam valley, and the hills of Arrakan and Bur- 

 mah. Only the later tertiary deposits in Sind, the Panjab, Northern India, 

 Assam, and Burmah are, as a rule, of subaerial origin and accumulated by 

 the action of fresh water, whilst in Sind there is distinct evidence that 

 the sea covered the greater portion, and very probably the whole, of the 

 country as late as the Miocene epoch.* 



§ 2. Zoological Relations between India and Africa. — The curious 

 points of connexion between the existing fauna of India and that of Africa 

 and the Mascarene islands bear out the idea of India having formed in past 

 times a portion of a great tropical continent. There also seems a probabi- 

 lity, as might have been anticipated, that at different geological periods the 

 distribution of land in this continental area varied, and that different por- 

 tions were in union with each other. Leaving aside the remarkable evi- 

 dence afforded by the Mesozoic (and Upper Palaeozoic ?) floras, amongst 

 which identical species have been found in Australia, Southern Africa, and 

 India, there appear to have been three distinct Tertiary and recent migra- 

 tions of African types into India, or perhaps it would be more correct to 

 say, that animals having affinities with those now inhabiting Africa have 

 entered India hi three different groups, two of which are older immigrants 

 than the other. The first consists of the types common to the Malay 

 countries, India, and Africa, which form a very large proportion of the 

 fauna : such as certain monkeys and lemurs, the Tragulidce, Viverra, Her- 

 pestes, Ulanis, and JSFectarinidce, Dicrttridce, Oriolidce, Pittidce, Bucerotidce, 

 JPIoceince, Megalaimince, &c.,&c, &c, Varanidce, Agamidce, &c.f As a rule 

 the African and Indian genera are distinct, but exceptions occur, as in Viver- 

 ra, Herpestes, Manis, Zosterops, Varanus, &c. Many of these forms extend 

 to Australia. 



The second group consists of forms common to India and Africa but not 

 found east of the Bay of Bengal nor yet in Arabia or Persia, such as Aniilo- 

 pidce (exclusive of G-azella), Mellivora, Chicquera. Syplieotides (= Lissotis), 



* Eecords G-eol. Surv. Ind. IX, p. 15. 



f See for fuller details * Africa-Indieir by A. v. Pelzeln in Verh. Zool.-Bot. (res. 

 Wien, 1875, p. 33. 



