INVERTEBRATES. 409 



MYRIAPODA 



? Genus ANTHRACERPES, M. and W. 



(ai/ifyaf, coal; epnw, to creep; — in allusion to its Carboniferous age, and proba- 

 ble habits.) 



Anthracerpes typus, M. and W. 



PI. 29, fig. 1, la. 



Anthracerpes typus, Meek and Worthen, May, 1865. Proceed. Acad. Nat. Sci., 

 Philad., p. 51. 



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

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

 sists of a well defined mould or impression left in a concretion, and measures 

 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 of very 

 uniform breadth or height, but it tapers very gradually towards what appears 

 to be the posterior end, where the last segment terminates in three or four 

 short, slender, hair-like, or spine-like appendages, directed backwards on a 

 line with the general curve of the body. The other end being broken away in 

 the only specimen yet known, the nature of the head and its appendages can- 

 not be determined. 



The entire body is distinctly articulated, and shows clearly nineteen seg- 

 ments, and part of another. The segments are of nearly uniform size, or only 

 vary from 0.08 to 0.10 inch in length ; the last one, however, has only a 

 breadth or height of about 0.03 inch, and the next about twice that. Crossing 

 the segments near the upper side, may be seen in the mould an undefined fur- 

 row (produced by a ridge in the fossil itself), which bends downwards and then 

 up again as it passes across from side to side of each segment. Anteriorly it 

 is less distinct and placed very near the dorsal margin, but in tracing it back- 

 wards it is found to descend and become more defined, until it reaches the 

 fourth segment from the extremity; on this it passes obliquely downward to its 

 posterior inferior corner, so as not to be seen on any of the succeeding divis- 

 ions behind. Below the middle of each segment, there is in the mould a small 

 prominence, evidently marking the position of a corresponding pit in the fossil. 

 These agree in position and appearance with the spiracles or breathing aper- 

 tures in the Myriapoda. We have not been able to make out very clearly, any 



52 Oot. 5, I860. 



