IX. Two New and Diverse Types of Carboniferous Myeiapods. 



By Samuel H. Scudder. 



Read April 5, 1882. 



CHARACTERISTICS of a distinct typa of carboniferous myriapods were recently given 

 in a paper on the Archipolypoda, or gigantic spined myriapods of the coal measures. In 

 collecting the material for that memoir some other striking forms fell under notice, which 

 at first were set aside as having no close connection with my studies; but which, with more 

 ample material and careful inspection, proved to be allied, though remarkably distinct. It 

 is the purpose of the pre -sent paper to bring these stranga forms to the notice of natura- 

 lists. They belong to two distinct types, each differing considerably from other known 

 ancient myriapods. One of these types is here noticed for the first time; the other and 

 more remarkable type is that figured in the Illinois Geological Reports, to which Messrs. 

 Meek and Worthen applied the name of Palaeocampa, and of whose affinities there has 

 been much doubt and some public discussion. 1 



For the opportunity of studying these interesting animals, the writer is entirely indebted 

 to his friends at Morris. 111., Messrs. J. C. Carr, P. A. Armstrong, and F. T. Bliss, who 

 have generously placed at his disposal the material they have, with great pains and 

 assiduity during a number of years, gathered in the nodules in the shales of Mazon Creek? 

 in that vicinity. 



The first of these new forms, to which the name of Trichiulus may be given, probably 

 belongs to the Archipolypoda. Five specimens of different species have been examined, 

 but they do not together furnish all the details that could be desired, even in those points 

 where most of the Euphoberiae and allied genera are sufficiently clear. They maybe de- 

 scribed (pi. 27) as jointed vermiform myriapods, tapering considerably from in front back- 

 ward. The segments of the body are unusually short and probably consisted of two ventral 

 plates to every dorsal plate, furnished profusely with rows of papillae, apparently ar- 

 ranged in definite series both longitudinally and transversely, and bearing long flexible hairs 

 which were sometimes much longer than the width of the body and formed a thick and uni- 

 form flowing mass entirely concealing the body. The body, and especially the hinder half, 

 was capable of being tightly coiled, as in modern lulidae ; more than this can hardly be said. 

 The relation of dorsal and ventral plates is by no means certain and is presumed mainly 

 from certain features which also occur in some obscure but indubitable specimens of Archi- 

 polypoda, and which are there referred with little doubt to a separation of the dorsal and 



1 Fur reference to this, see the bibliographical citations under the description, infra, of Palaeocampa anthrax. 



MKMOIKS MOST. SOC. NAT. HIST. Vol.. III. 37 



