XL Illustrations of the Cakboniferous Arachnida of North America, of 



THE ORDERS AnTHRACOMARTI AND PedIPALPI. 



By Samuel H. Scudder. 



Read May 7, 1800. 



Ti 



IIE present paper contains a discussion of all the carboniferous Arachnida of Amer- 

 ica, excepting Arthrolycosa, of which Mr. C. E. Beecher has lately given a fuller and 

 moi-e correct account than we have had before, and the scorpions, which will be treated 

 on a future occasion. The descriptions of the previously knoAvn species are more de- 

 tailed than at first, other new forms are added, and illustrations are given of all, except 

 of Architarbus rotundatum, -preVwusly figured; with that exception it is the first attempt 

 to figure the American forms in these groups. It should be added, however, that since 

 these illustrations were pi-epared, further material has come to my hand, mostly from 

 the rich collections of Mi-. Lacoe and of Mr. Gurley, which may still farther extend 

 the list, but I have been obliged to leave them for another occasion. 



■C3"- 



Order ANTIIRACOMARTI Karsch. 



Body somewhat depressed, the cephalothorax and abdomen distinctly separable. Ce- 

 phalothorax usually made up in large part of more or less wedge-shaped pedigerous seg- 

 ments, the arrangement of which corresponds to that of the coxae. Abdomen forming 

 a single mass and composed of from four to nine distinct joints. Palpi not much longer 

 than the legs and simjily terminated. 



This group, the only extinct order of Arachnida, was established by Karsch for some 

 interesting cai-boniferous forms of somewhat obscure relations allied to the Phrynidae 

 and Phalangidae, but very distinct fi-om either of them. Its position seems to be be- 

 tween the Chelonethi and the Pedipalpi, to the latter of which it bears perhaps the 

 closest relations. The Anthracomarti were the most varied in structure and, with the 

 possible exception of the scorpions, the most abundant in species of the carboniferous 

 Arachnida, and being unknown after that ])eriod they maybe considered the most char- 

 acteristic of paleozoic Arachnida. The foi-ms here considered belong to two distinct 

 families. 



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