CARBONIFEROUS MYRIAPODA OF ILLINOIS. 419 



are even more prominent than in Scutigera and notwithstanding the more i-obust body 

 jiroject much further beyond the sides; but in addition the femora are of excessive length 

 and slenderness, slenderer than the coxae and half as long again as the width of the very 

 broad body, and taper from base to apex; to judge by appearances these two members 

 constituted the larger, instead of as in Scutigera the smaller, part of the leg, but this can- 

 not be asserted; x^i-obably however the tibiae and the (multiarticulate?) tarsi together were 

 no longer than the femora. 



The genus is named in honor of Dr. Robert Latzel of Vienna who has so much ad- 

 vanced our knowledge of the Myriapoda. 



Latzelia primordialis sp. nov. 

 PI. 38, fig. 3. 



The single specimen is found in a small nodule which at the two extremities cuts off 

 the appendages, but offers no hindrance to the full expanse of the members laterally, 

 though their full length cannot yet be seen. The main features have been described 

 above under the family and genus, both of which have their source in this single speci- 

 men. No part of the antennae is preserved. The body segments, however, show a 

 peculiar structure; not only are the front and hind margins entire and transverse, per- 

 mitting no opening to the position of the mediodorsal stomata found in Scutigera, but 

 most of the segments (all where not obscure) show a distinct, marked and shai'p medio- 

 dorsal carina extending the whole length of each segment, but somewhat obscure poste- 

 riorly over just about so much of the dorsal shield as in Scutigera is emarginate for the 

 stomatal opening; and on either side of this carina, all the segments, but especially the 

 median ones, show a pair of diverging sulci, twice as distant posteriorly as anteriorly, 

 crossing the entire segment, and posteriorly as far apart as the length of the segment; 

 sometimes also showing faint traces of continuing upon the segment next posterior. The 

 body itself is slightly arched transversely. 



The legs are similarly constructed, but the median ones are evidently stouter than 

 those at the extremities, to a slight degree. Both coxae and femora show the median 

 half transversely arched, while the sides show notliing of the sort, or sometimes interior- 

 ly, next the transverse arching, a broad longitudinal sulcus, all giving the appearance 

 of a depressed leg with a median rounded longitudinal ridge, veiy common in the Archi- 

 polypoda. 



Length of body, 22.5 mm. ; breadth in middle, 4.5 mm. ; length of coxae in middle of 

 body, 2.3 mm.; of femora in same, 6.5 mm.; breadth of same coxae, 0.9 mm.; breadth of 

 same femora at base, 0.7 mm. ; at tip, 0.5 mm. 



Mazon Creek. Mr. R. D. Lacoe, No. 1837ab. 



EOSCOLOPENDEIDAE fam. nov. 

 Head evidently formed of two principal segments, but these much more closely fused, 

 separated only by sulcations or blind sutures. Body segments numerous and similar, 

 each bearing a single pair of legs and havuig a single dorsal and ventral plate, the former 



