OF CARBONIFEROUS MYRIAPODS. 293 



mm. in length, and its extreme breadth is 14 mm. The head end is broken badly but 

 enough is preserved to show that it tapered anteriorly, the largest part of the body being 

 probably the end of the anterior third ; beyond this the body tapered gently to very near 

 the tail, but then diminished very rapidly in size, the tip, however, being rounded; a little 

 before the rapid diminution in size the diameter is 9 mm. There seem to have been about 

 thirty-five segments to the body, about four times as broad as long on the average, not 

 very much arched and least so along the upper portion, where, at least in the fossil, the 

 surface is almost completely flat and shows scarcely a sign of the divisions of the segments. 

 In certain parts of the fossil there are indications of minute tubercles as if for the support 

 of hairs, but they are obscure and would not have been noticed but for their occurrence 

 in the preceding species. There is, however, along the outer edge an exceedingly faint 

 indication of a delicate mat of very fine hairs, where the surface of the stone, as in T. 

 villosus, is decidedly darker than elsewhere. This specimen also was found by Mr. P. A. 

 Arms tiong in the nodules of Mazon Creek. 



Suborder PROTOSYNGNATHA. 



Palaeozoic myriapods, with a cylindrical bony, the head appendages borne upon a single 

 segment; each segment behind the head composed of a dorsal and ventral plate of equal 

 length and, probably, of subequal breadth ; the dorsal at least somewhat broader than the 

 ventral, occupying the greater part of the sides of the body, and supporting several longi- 

 tudinal rows of clustered needles ; the ventral plates occupying the entire ventral portion, 

 each bearing a pair of widely separated, stout, fleshy legs, i. e., one pair to each segment 

 of the body behind the head; spiracles probably present in a definite longitudinal row. 



GenUS PALAEOCAMPA (iraXaids; Ka'umv) 



Palaeocamjja, Meek and Worthen, Proc. Acad. Nat. Sc. Philad., 1865, p. 52 (1865); — 

 lb., Geol. Surv. 111., 2 : 410 (1866). 



Desmacanthus, Meek and Worthen, Geol. Surv. 111., 3 : p. 565 (1868). 



Head corneous with no armature. Body coriaceous, coarsely shagreened, composed of 



ten segments furnished on each side with two rows, dorsolateral and lateral, of fascicles of 



needle-like spines, one to a segment in each row, placed upon tubercles near the front of 



the segments ; the fascicles are cylindrical at base, the needles diverging only a little ; 



each needle tapers very slightly, is blunt at tip, and very regularly divided by longitudinal 



serrated ridges. Legs stout, subequal, about as long as the width of the body, tapering 



and pointed. 



Palaeocampa anthrax, Meek and Worthen. 



PI. 26. 



Palaeocamjm anthrax, Meek and Worthen, Proc. Acad. Nat. Sc. Philad.. 1865, pp. 52-53, 

 (1865); Palaeont. 111., Vol. 2, pp. 410-411, pi. 32, fig. 3 (1866); — lb., Vol. 3, p. 

 565 (1868) ; Scudder, Geol. Mag., Vol. 5, p. 218 (1868). Figured also in Packard's 

 Guide to Study of insects, fig. 68 on p. 78. 



