NATURAL SCIENCES OP PHILADELPHIA. 51 



oblique articulation of the second and third joints of the peduncles, to be 

 their natural position. (Inner antennae unknown.) 



Immediately between the bases of the two outer antennae, the specimen 

 shows what appear to be impressions of the two globose eyes, which with 

 their peduncles extend forward about two-thirds as far as the peduncles of 

 the antennre. These may possibly be the peduncles of the inner antennae; 

 but they look very much like globular eyes, on more slender peduncles. 



The abdomen is more than half the length, and about two-thirds the 

 breadth, of the widest part of the carapace. It shows five short segments, 

 and apparently part of another, the first of which is a little smaller, and the 

 second a little larger than the others. None of them, however, are more than 

 one-fifth as long as the breadth of the abdomen. 



The caudal appendages being unfortunately bent down and crushed, 

 it is not possible to make out the form of the telson or the details of the 

 other parts, though the whole together seem to have been wider than the 

 abdomen, and as wide as the carapace. No surface sculpturing can be clear- 

 ly made out, though there is some appearance of a few irregular scattering 

 granules near the margins of the carapace. (Other parts unknown ) 



Entire length, from the stalked eyes? to the extremity of the caudal ap- 

 pendages, about 1-13 inches; length of carapace, 0-63 inch ; breadth of do. 

 near the middle, 0-45 inch; at the extremities 0-31 inch; length of abdo- 

 men, 0-30 inch ; breadth of do. near the middle, 0-26 inch. Length of pe- 

 duncles of the antenna? 0-15 inch ; do. of eyes ? and their peduncles, 0-13 inch. 



It will be observed from the foregoing description that our specimen 

 shows no traces of the central spine or beak, extending forward from the 

 anterior extremity of the carapace, nor of the longitudinal carina connected 

 with it, which constitutes such a marked feature in Anlhrapalsemon. It is 

 possible, however, that this character may have been obliterated in breaking 

 open the concretion, since our specimen only shows an impression of the 

 under side of the carapace, while the appendage alluded to projects forward 

 from the upper side, and may consequently be embedded in the other half of 

 the concretion, which we have been unable to obtain. Still as it is possible 

 that this appendage may be wauting in our fossil, we should not be sur- 

 prised if it would prove to belong to an allied but distinct genus. 



Specifically at least, it differs from A. Grossartii, of Salter, in the propor- 

 tionally much shorter joints of the flagella of its outer antennae, and the 

 oblique articulations of the segments of their peduncles ; while the latter, as 

 well as the surface of other parts, are without any traces of the fine pitting 

 represented by Mr. Salter's figures. Our specimen also shows traces of what 

 appear to be squarely truncated basal scales to the outer antennae, about as 

 long as their first joints, while. Mr. Salter's figure (1), represents apparently 

 a triangular scale over the left antenna. 



Length from the end of the caudal extremity, to the anterior margin of the 

 carapace, 1 inch. Length of carapace, 060 inch; breadth of do. 0-43 inch. 

 Length of abdomen, about 030 inch; breadth of do. 0-27 inch. Length of 

 caudal appendages, 0-10 inch. 



MYRIAPODA. 



? Genus ANTHRACERPES, Meek & Worthen. 



Anthracrrpes typus, M. & W. 



This genus and species are founded upon a slender worm-like fossil, the 

 relations of which have not been very clearly determined. The specimen 

 consists of a well defined mo^ld or impression left in a concretion, and meas- 

 ures 1-50 inches in length, and about 0-09 inch in breadth, (height) as seen 

 lying upon one side. It is regularly arched from end to end, so as to form 

 about one-third of a circle of 0-65 inch radius. For most of its length, it is 



1865.] 



