AIR-BREATHEKS OF THE COAL. 
415 
Fig. 442. 
a 
head, with the eyes, mandible, and labrum, are well seen. It 
is interesting, as being the earliest known representative of 
the myriapods, none of which had previously been met with 
in rocks older than the oolite or lithographic slate of Ger¬ 
many. 
Some years after the discovery of the first Pupa, Dr. Daw¬ 
son, carefully examining the same great section containing so 
many bm-ied forests in the clifis of Nova Scotia, discovered 
another bed, separated from the tree containing Dendrerpe- 
ton by a mass of strata more than 1200 feet thick. As there 
were 21 seams of coal in this intervening 
mass, the length of time comiDrised in the 
interval is not to be measured by the 
mere thickness of the sandstones and 
shales. This lower bed is an underclay 
seven feet thick, with stigmarian rootlets, 
and the small land-shells occurring in it 
are in all stages of growth. They are 
chiefly confined to a layer about two 
inches thick, and are unmixed with any 
aquatic shells. They were all originally 
(‘utire when imbedded, but are most of 
them now crushed, flattened, and distort¬ 
ed by pressure ; they must have been ac¬ 
cumulated, says Dr. Dawson, in mud de¬ 
posited in a pond or creek. 
The surface striae of Pupa vetusta^ when 
magnified 50 diameters, present exactly 
the same appearance as a portion corresponding in size of 
the common English Pupa juniperi^ and the internal hex¬ 
agonal cells, magnified 500 diameters, show 
the internal structure of the fossil and re¬ 
cent Pupa to be identical. In 1866* Dr. 
Dawson discovered in this low^er bed, so 
^ full of the Pupa, another land-shell of the 
^ genus Helix (sub-genus Zonites), see Fig. 
443. 
„ . None of the reptiles obtained from the 
Zomtes{Conulus)pnfiCUS, , t • ^ 
Carpeuter. a. Natural coal-measures 01 the houth Joggms are of 
size. b. Magnified. ^ higher grade than the Labyrinthodonts, 
but some of these were of very great size, two caudal verte¬ 
brae found by Mr. Marsh in 1862 measuring two and a half 
inches in diameter, and implying a gigantic aquatic reptile 
with a powerful swimming tail. 
Except some obscure traces of an insect found by Dr. 
* Dawson, Acadian Geology, 1868, p. 385. 
Pupa vetiista, Dawson. 
a. Natural size. b. Mag¬ 
nified. 
