JONES— TKATLS, TEACKS, AND SUEFACE-MARKINGS. V-15 
thougli they may have been due to birds. I may mention, that a 
friend in India (Mr. R. N. Mantell, since deceased) described to me 
in a letter, some large, broad, trifid markings that he saw on the sand- 
banks of the Ganges ; they were of this shape (fig. 7), shallow, and 
with a well-definededge. Tracing 
the track to where the sand was 
wet, he found them take the un- 
mistakeable and unpretending 
shape of ordinary bird-tracks (fig. • 
8) ; " the sole and sufficient rea- 
son," said he, "of their gross ex- 
aggeration was the action of the ^• 
wind on the fine dry sand." Trying prints of his own hand, he saw 
them slowly become augmented into broad caricatures of a hand-print 
by the same natural process. 
On the figured slab of Wealden rock, from the Upper Hastings 
Series, near Cuckfield, Sussex (PI. VII.), we have sun-cracks, raised 
gallery-markings, and many obscure trails, some corrugated, some 
smooth. It is possible that, as a friend has suggested to me, some of 
these may be the marks of roots of aquatic plants ; but there is no 
direct evidence on the subject. Root-like markings, however, small, 
vertical, and numerous, occur abundantly in the Hastings sand-rock, 
as pointed out to me by my friend Mr. J. Morris (see fig. 9). 
During the autumn of the same year as tliat in which I collected 
the recent trail-marked mud in the Isle of Wight, I was in the Weald 
of Kent, and, examining a brick-field, I saw a pond lessened by 
drought, and on its mud were prints of a dog's feet, small hollow 
trails, and convex galleries, such as those before noticed (fig. 10). 
The roofs of some of these last were so thin they were split, and in 
some cases removed. Besides the markings above mentioned, the dry- 
ing clay had another interesting feature, namely, a partial coating of 
minute globular bodies (fig. 10 a), mostly lying closely packed in single 
layer, but sometimes crowded irregularly, and occasionally scattered 
about loosely. These are of the same colour as the clay, and are 
probably the ova of the Boat-fly {Notonecta) , thinly coated with clay ; 
and their interest lies in the fact that in Mexico allied insects are 
known to lay a profusion of large ova in the Lake of Tezcuco, and 
that there they become petrified into an oolite. The fact has been 
described by M. Virlet d'Aoust, in the ' Bulletin de la Soc. Geol. de 
Trance,' 2e Ser., vol. xv. p. 200, etc., 1858, who, noticing the oolitic 
structure of the recent limestone on the margin of the salt-water 
lake of Tezcuco, near Mexico,* learnt from Mr. J. C. Bo wring, the 
manager of the salt-works there, that the oolitic granules were nothing 
more than the eggs of certain insects, encrusted and cemented toge- 
ther by the calcareous sediment of the lake. The eggs, too, being 
attached by little stalks or pedicels, are the more readily coated with 
the lime all over, and keep their relative position the more firmly. 
* See the memoir for some interesting information on the relationships of the great 
freshwater and salt lakes of the Mexican plateau ; also, E. B. Tylor's ' Anahuac,' 1859. 
