154 .S. II. SCUDDER ON SPINED MYRIAPODS 



tion, measurements of the second joint showing no difference whatever. The length of the 

 first joint is 2.4 mm. ; of the second 7.75 mm.; width of same 1.2 mm. ; length of third joint 

 2.2 mm.; of fourth joint 2.2 mm.; of fifth joint 2.2 mm.; of sixth joint 2. mm.; of the whole 

 leg as it lies on the stone 21 mm. So far as the legs are preserved there are two pairs to 

 every dorsal plate ; the stone is broken away next the last two segments so that they do 

 not show there, one only appearing on the penultimate, none on the last segment ; the same 

 is true in front, so that none appear on the first segment behind the head, and only one on 

 the second segment ; but this one is placed posteriorly, leaving room for an additional one 

 in front of it on the same segment. 



Along the ridges which separate the bases of the two sets- of legs (of opposite sides) 

 from each other can be seen remnants of the branchial cups to be mentioned further on, but 

 in a fragmentary and often somewhat displaced condition ; enough however to show clearly 

 to one who has studied the specimen next to be described that they were present here 

 throughout the greater part of the body, as they can be traced in various parts. 



Both relief and intaglio of this- specimen are preserved and have helped to reconstruct 

 the myriapod as we have attempted to depict it. They belong to Mr. J. C. Carr of 

 Morris, Illinois, from whom, through the kind intervention of Mr. J. W. Pike, in whose 

 hands I first saw it, it was received for study. 



Notwithstanding its far greater incompleteness, the next specimen (PI. 11, figs. 1-4) of 

 this species to be mentioned rivals the one just described in interest and importance, on 

 account of its perfect exhibition of the ventral plates. It consists of only a few segments 

 from the stouter part of the body, probably presenting an oblique view, mostly dorsal, with 

 a cast of the same. In the breaking of the stone, the part representing the former under 

 crust of the animal has in a small part of the fossil parted from the upper crust, so that in 

 looking upon the dorsal surface one sees also, in the central part of the fossil, the interior 

 view of the ventral plates ; and its cast represents, no doubt with tolerable faithfulness, the 

 appearance of the under surface of the ventral plates. The body is a little curved and 

 the posterior segments parted from one another. The convexity of the upper surface of 

 the body well appears, but the form of the body cannot further be told from this specimen. 

 The fragment is 67 mm. long as it lies, but this should be reduced to about 58 mm. to allow 

 for the displacement of the posterior segments. It is 17-18 mm. broad and shows no sign 

 of tapering ; probably it is a fragment from the broadest part before the tapering had com- 

 menced ; on that supposition its size indicates a creature rather larger than the complete 

 specimen last described, but not so large as that described by Meek and Worthen. Eleven 

 segments are present, four anterior ones in their natural relations showing the dorsal plates ; 

 then three, also connected with one another and the preceding, but of which the dorsal 

 plates are gone, revealing the inner surface of three pairs of ventral plates ; and finally 

 four more dorsal plates separated from one another by more than their own length. The 

 dorsal plates are from 3.75-4.5 mm. long and therefore about four times as broad as long, 

 their anterior half bearing a broadly rounded, elevated, transverse ridge with mammiform 

 knobs which are the broken bases of the spines ; the posterior edges of the segments are 

 also a little thickened and slightly elevated, giving the appearance of a slight transverse 

 ridge at this point. The surface appears to be almost or quite smooth ; in one or two 

 points a delicate granulation may be seen under a strong lens, and next the hinder edge of 



