2G MALLET: ADEN AND VICINITY. 



sandstone being met with near tlie junction witli c, there being a passage 

 from h into c showing that both belong to the same formation. Similar 

 bands also occur in the lowest portion examined^ so that the strata at a 

 are not improbably sandstone. The limestone abounds in fossils numeri- 

 cally, although the number of species does not seem to be very large. 

 Dr. Stoliczkaj who has examined the specimens I obtained, observes 

 respecting them that the " limestone is full of sections of a long turreted 

 Nerinea, a species of Cryptoplocus, of a Pelecypod, probably a Corbis, 

 and large mimbers of a Sjoongites, generally dichotomous. The limestone 

 is evidently of mesozoic age, and the few fossils appear to resemble most 

 upper Jurassic forms, though the same genera also occur in lower creta- 

 ceous beds.'''' The sandstone is white, grey, or reddish. It is a coarse 

 rock, pebbly in places, the pebbles being of red and white quartz. 

 From c to e is fully 2,000 feet. The dip of the limestone and sandstone 

 is south-west at about 40°, which is more or less the dip of the beds in 

 all the neighbouring hills. In one, some distance to the north-west, 

 however, the dip is reversed to north-east at -40°. Lines of stratification 

 are visible in the hills to the north and north-west as far as one can see. 



At Ulkhour, 25 miles to the eastward, the outermost hills are of grey 

 limestone, lithologically quite similar to that north of Majhafa, but I 

 observed no fossils in it. In one place it contains a thin band of quartzite, 

 and I also remarked a dyke of earthy trap, cutting nearly vertically through 

 the bedding. The limestone is several hundred feet thick, with an easterly 

 irregular dip of about 30° ; the hills to the west are also of stratified rock, 

 and I believe the latter is continuous to where I examined them north of 

 Majhafa. 



In the Hassan river where I crossed it two or three miles below 

 Ulkhour, pebbles, and even boulders of a foot diameter, of metamorphic 

 and volcanic rocks are abundant. The former include gneiss, in which the 

 foliation is distinctly seen, composed of red felspar, quartz, and dark 

 green mica, and a somewhat similar rock without foliation which may 



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