286 Mr. S. H. Scudder on the Affinities of 
XXVIII.— The Affinities of Paleocampa, Meek and Worthen, 
as Evidence of the wide Diversity of Type in the earliest 
known Myriopods. By SAMUEL H. SCcUDDER*. 
In an article on the structure of Huphoberia of the Mazon 
Creek nodules, published in this Journal a year ago f, the 
wide departure of modern myriopods from their ancient allies, 
in structure, general appearance, and habits, was clearly 
pointed out by detailed comparisons between the relics pre- 
served in the Carboniferous rocks and the corresponding parts 
in modern types. A considerable number of specimens of 
Archipolypoda, as the ancient forms were termed, bearing out 
in every particular the points then brought forward, have since 
been examined, and have been fully represented in an illus- 
trated memoir just published by the Boston Society of Natural 
History. Thanks to the local naturalists who have so well 
explored the beds of Mazon Creek, and who have furnished 
nearly all the material for the papers mentioned, I shall now 
attempt to show that Palcocampa is neither the caterpillar of 
a lepidopterous insect, nor a worm{, but a myriopod of another 
new and strange type. Messrs. Carr and Bliss, of Morris, 
Ill., have sent me three specimens of Paleocampa in fine 
condition, better preserved and a little larger than the original, 
which has been lost by fire. Messrs. Meek and Worthen 
have also examined a second specimen; so that five in all 
have now been studied. Only one of these, that procured by 
Mr. Bliss, is preserved in such a way as to show the legs ; 
and, until its discovery, the affinities of this animal would 
necessarily have remained very obscure. 
But for my previous study of the Archipolypoda of Mazon 
Creek, and the revelation which these ancient types give of 
the divergence of structure between extinet and modern forms 
of Myriopoda, it would have been difficult to reach the full 
conviction that Paleocampa was a myriopod. It is a cater- 
pillar-like segmented creature, 3 or 4 centim. long, composed 
of ten similar and equal segments besides a small head; each 
of the segments excepting the head bears a single pair of 
stout, clumsy, subfusiform, bluntly-pointed legs, as long as 
the width of the body, and apparently composed of several 
equal joints. Each segment also bears four cylindrical but 
* Amer. Journ. Sci., Sept. 1882, pp. 161-170. Read before the Na- 
tional Academy of Sciences, in April 1882. 
+ Ann. & Mag. Nat. Hist. for June 1881, p. 487. 
{ Cf. Meek and Worthen, Proc. Acad. Nat. Se. Philad. 1865, p. 52; 
eosd, Geol, Sury, Ill. vol. ii. p. 410, pl. xxxii. fig. 3, vol. iii. p. 565; Scudder, 
Geol. Mag. vol. v. p. 218. 
