M. A. Grandidier on the Egg-beds o/iEpyornis. 67 



The dunes, which extend on the south coast of Madagascar 

 from longitude 42° 44' to 43°25'E., are only separated from the 

 sea by a very narrow flat beach, of not more than 3 or 4 metres 

 in breadth, covered with a quartzose sand, plentifully mixed with 

 garnet. These dunes, the slope of which often measures more 

 than 60°, rise to a height of 143 metres ; their perfectly recti- 

 linear suumiit gives them the appearance of fortifications made 

 by the hand of man, rather than the work of the wind. They 

 are composed of the remains of shells, reduced to an impalpable 

 dust, and of very fine grains of quartz. At their base I have 

 collected Lucina tigerina, L., and a coral of the genus Favia, 

 species belonging to the Indian Ocean ; but it is on their slopes 

 that the fragments of the eggs of j^pyornis are found, mingled 

 with the remains and moulds of land-shells: — 1st. Bulimus fa- 

 vannii*, Fer. ; 2nd and 3rd. B. affinis (sp. n.), B. crassilabris, 

 Gray, B. clavator, Petit, B. obturatus, Reeve; 4th. Helix (sp. 

 ind. ); 5th. Chjclostoma (sp. ind.). I have very seldom found 

 organic remains in digging in this deposit or in traversing the 

 higher plateau. 



The rains, as well as the winds, carry away only the finest 

 sand, leaving the shells and the fragments of eggs, which they 

 have denuded, gradually to accumulate on the steep slopes; it is 

 in fact in the parts destitute of vegetation, and above all in a 

 little ravine where the waters have left evident traces of their 

 efi'ect, that I have collected the greater part of the organic 

 remains which I have the honour to submit to the inspection of 

 the Academy. The places protected fi-om denudation by the 

 prickly vegetation and the stunted shrubs characteristic of that 

 region, do not present anything like the same abundance of 

 subfossils. 



With the shells are sometimes found mixed calcareous stones, 

 still angular, although rolled, in size varying from that of a 

 cannon-ball to that of a bullet ; but, abundant as they are on 

 the surface of the higher plateau, and on the slopes sheltered 

 by shrubs, they are somewhat rare on the denuded slopes. 



On the top of the dunes, only plains covered with stunted 



* This subfossil Bulimus has partly preserved its colours. It still lives 

 in the island of Madafjascar. 



f2 



