422 SAMUEL H. SCUDDER ON NEW 



the body is composed, each accompanied by a single pair of legs. What is peculiar about 

 it, is not only its tapering foi-m anteriorly but its great attenuation at this extremity, in- 

 dicating apparently a remarkably small head followed by a slender neck of at least two 

 elongated segments, which do not appear to be pedigerous ; these neck-segments are 

 fully twice as long as bi-oad, and not only do the segments behind them taper as they 

 approach them, but the anterior of these two is the smaller and narrower and not a fourth 

 nor probably a sixth as broad as the broadest segments of the body. The legs are poor- 

 ly preserved, about as long as the breadth of the body (relatively longer in front) and 

 apparently have very prominent coxae, as in other carboniferous myriapods. 



Palenartlirus impressus sp. nov. 

 PI. 38, fig. 4. 



The single specimen probably represents nearly the whole animal, though neither end 

 is shown; it is hai-dly probable that anything more than the head is wanting at the an- 

 terior extremity, but posteriorly an indefinite number of segments. There are twenty- 

 three segments in all. The first two behind the head are slender and twice as long as 

 broad, the third subqnadi-ate, the four or five succeeding broader than long, of subequal 

 length, but increasing breadth in passing backward; thereafter they appear to be of the 

 same size, about twice as broad as long and rectangular, the front outer angle sometimes 

 a little produced. The first two elongated segments show a slight median carina ; the 

 fourth and succeeding ones on either side a laterodorsal series of large circular depres- 

 sions next the anterior edge. 



Length of fragment, -iO mm. ; breadth of first body segment, 1 mm. ; of seventh, 5 mm. ; 

 length of legs, 3 mm. 



Mazon Creek. Mr. K. D. Laeoe, ISTo. 1821ab. 



Iltodes gen. nov. (i^omSTjc;) 

 I venture to propose this name for some obscure forms in the hope of stimulating 

 further search for more perfect specimens to elucidate their structure. One of them is 

 plainly chilopodiform, though veiy different from anything we know; there is certainly 

 but a single pair of legs to each segment, though the line of separation of the segments is 

 obscured by the curious transverse sculptiire of the dorsal plates; but we ai'e aided in 

 our determination by the presence of serial tubercles. These latter, or their reverses, also 

 occur on the taenioid body of a second form which has no legs preserved, and which is 

 provided with such a multitude of short transverse segments that it would seem impos- 

 sible that it could have possessed more than a single pair of legs to each; it reminds us 

 somewhat of Geophilus. The only points these have in common are that they are com- 

 posed of a large number of similar transverse segments each bearing a single pair of 

 legs and furnished Avith serial rows of tubercles. 



Ilyodes divisa sp. nov. 

 ri. 38, lig. 1. 

 The single specimen referred here is a straight fragment composed of fourteen simi- 



