290 Mr. 8. H. Scudder on. the Affinities of 
find that its body was, in all probability, cylindrical, composed 
of a limited number of segments behind the head, and the 
head itself, considerably smaller than the body-segments, is 
composed of only a single apparent segment. The legs of the 
segment immediately succeeding it are in every respect like 
those of the rest of the body, and have nothing whatever to 
do as auxiliary to the mouth. In this point alone we have a 
distinction as wide and incisive as any which separate the 
modern Diplopoda and Chilopoda. In the body-segments we 
discover no trace of any thing more than a simple ring without 
subdivision ; but as the specimens indicate a coriaceous struc- 
ture like that of modern Chilopoda, and no trace of the 
division between the dorsal and ventral plates can be seen in 
any of them, the separation of the segments into two sub- 
segments, as in Chilopoda, one of them greatly atrophied, 
could hardly be apparent did it exist. But on the other hand, 
as we regard the second subsegment of Chilopoda as atrophied, 
we should expect to find it fully or partially developed in these 
creatures, which of all known ancient types are certainly the 
most closely related to them. Yet we find here no sign of 
any thing more than the simplest possible, uniform, leg-bear- 
ing segments, and of a very limited number. In one feature, 
however, they are not so simple as in Chilopoda; for, as 
stated, each is provided on each side with two pairs of ma- 
mille, supporting very large bunches of spreading rods, and 
the rods themselves sculptured in a very remarkable way. 
This distinction between the two types, though more striking 
and noticeable than any other, is in itself by no means so 
important as the others, but may be added to the catalogue ; 
and it must have some weight, from the total absence of ap- 
pendages of any sort (beyond scattered hairs) from the dorsal 
plates of Chilopoda. ‘The position of these rows of fascicles 
and of the legs indicates that the ventral plates are only a 
little narrower than the dorsal, and probably of about the 
same extent as in the Archipolypoda; in this respect they do 
not differ to any important degree from modern Chilopoda. 
The legs were different in form; but their poor preservation 
in the only specimen in which they have been seen prevents 
any thing more than the mere statement of the following 
difference: while the legs of Chilopoda are invariably horny, 
slender, adapted to wide extension and rapid movement, 
those of Paleocampa are fleshy, or at best subcoriaceous, 
very stout and conical, certainly incapable of rapid move- 
ment, and serving rather as props. 
These differences, which underlie every part of the body 
that is preserved in Palewocampa, show that while the general 
