Morphology of the Myriopoda. 349 
Protochilopoden.” He proposes a hypothetical group, Proto- 
symphyla, from which the Symphyla, Thysanura, and Chilo- 
poda have originated. But, as we have seen, this view is 
based on mistaken views as to the relations of the Chilopods 
to the Diplopod Myniopods, and of the homologies of Myrio- 
pods with Insects. As we have seen, the Chilopods must 
have originated from a Chilognathous stock, or at least from 
a branch which arose from Pawropus-like forms, and the 
Thysanura, with Scolopendrella, must have arisen from a 
separate main branch, which led to the Hexapodous branch 
of the Arthropod genealogical tree. 
For the reasons stated, also, we should disagree with the 
views of Hiickel (‘ Natiirliche Schépfungsgeschichte,’ 1870, 
2nd edit.) that the Diplopod Myriopods were derived from 
the Chilopoda. In the English translation (1876) he re- 
marks, ‘‘ But these animals also originally developed out of a 
six-legged form of 'Tracheata, as is distinctly proved by the 
individual development of the millipede in the egg, Their 
embryos have at first only three pairs of legs, like genuine 
insects, and only at a later period do the posterior pairs of 
legs bud, one by one, from the growing rings of the hinder 
body. Of the two orders of Centipedes .... the round 
double-footed ones (Diplopoda) probably did not develop until 
a later period out of the older flat s¢ngle-footed ones (Chilo- 
poda), by successive pairs of rings of the body uniting toge- 
ther. Fossil remains of the Chilopoda are first mentioned in 
the Jura period.” The Chilognaths, however, as shown by 
Dawson, Meek, and Worthen, and latterly by Scudder, were 
numerous as far back as the Carboniferous period; the Chilo- 
pods are the later productions, perhaps not older than the 
Tertiary period, since Germax’s Geophilus proavus is a doubt- 
ful form. 
In this connexion reference should be made to the singular 
fossil, Paleocampa, from the Carboniferous formation of Ih- 
nois, originally described as a caterpillar-like form by Meek 
and Worthen, and lately claimed to be a Myriopod by Mr. 
Scudder*, who proposes for the hypothetical group, of which 
he considers it as the type, the name Protosyngnatha. It 
seems to us, after a careful reading of Mr. Scudder’s article, 
that this obscure fossil presents no features really peculiar to 
the Myriopods, but that there are as good or better reasons 
for regarding it as the hairy larva of some Carboniferous 
neuropterous insect. Mr. Scudder describes it substantially 
* “The Affinities of Paleocampa, Meek and Worthen, as evidence of 
the wide diversity of type in the earliest known Myriopods,” by Samuel 
H. Scudder. Amer. Journ. Science, xxiv. no. 141, p. 161 (Sept. 1882), 
Ann. & Mag. N. Hist. Ser. 5. Vol. xii. 25 
