X. New Carboniferous Mtriapoda from Illhstois. 

 By Saiviuel H. Scudder. 



Read May 7, 18'J0. 



J_ HE publication of my paper on Archipolypoda, eight years ago, in which a consider- 

 able number of new types of American carl)ouiferous Myriapoda were described, has so 

 stimulated search in this country that, thanks to the kindness of many friends and par- 

 ticularly of the indefatigable Mr. R. D. Lacoe, there has since passed under my eyes a 

 much greater number of specimens than I had then seen, and as they contain not a few 

 additional and some remarkable forms, as well as throw more light upon the old, it has 

 seemed well to bring them together in a systematic way, and to present some tables by 

 which they may be distinguished, when sufficiently perfect. Accordingly there are here 

 published such as have been found at Mazon Creek and vicinity leaving for a future pa- 

 per several new forms which have been found in the sigillarian stinnps of ISTova Scotia. 

 The sources from which the specimens were received are in all cases indicated, and the 

 paper concludes with a summaiy list of known American species of palaeozoic Myi-ia- 

 poda. 



TABLE OF THE ORDERS OF PALEOZOIC MYRIAPODA. 



Each of the principal body segments composed of a single dorsal and single ventral plate, each of the latter with a pair of 

 legs. Body usually unarmed. 

 Head apparently formed of a single segment. Dorsal plates of body supporting clusters of needle-like spines on 



serially ranged tnbercles. Legs stout and fleshy Protosyngnatha. 



Head apparently formed of two or more segments. Dorsal plates of body sometimes furnished with lateral expan- 

 sions but otherwise unarmed. Legs slender and horny Chilopoda. 



Each of the principal Ijody segments composed of a single, but more or less distinctly divided dorsal plate and a |iair of 

 ventral plates, each of the latter with a pair of legs. Body generally armed with spines or tuljcrcles serially ar- 

 ranged Archipolypoda. 



Only the Chilopoda and Archipolypoda will be considered in the present paper, as I 

 have nothing to add concerning Palaeocampa, the sole representative of the Protosyn- 

 gnatha. 



Order CHILOPODA Latreille. 

 It has not been supposed that this group of myriapods reached further back than the 

 Jura 01" even than the tertiaries, for its only claim to recognition in the secondary rocks 



MEMOIua BOSTON 800. NAT. UlST., VOL. IV. 56 ('tl') 



