THE TERTIARY PHYSOPODA OF COLORADO. 



By Samuel H. Scudder. 



Some years ago * I described a genus of fossil Physopoda from the 

 IsTorth American Tertiariea. Since then I have found other species among 

 the specimens collected by Prof. William Denton, and bring together in 

 this place a connected account of all of them. They all belong to the Tere- 

 irantia. Species of Physopoda have been found in a fossil state in other 

 places. Thus, Menge has described three species from the Prussian 

 amber, and Oastalet, in a communication before the Societe Philo- 

 mathique of Paris (still I believe unpublished), gave the characters of 

 several species from Aix, in Provence, in addition to the one long since 

 described by Heer, from the same beds. 



Melanothetps extincta, nov. sp. 



Head small, tapering; the only appendages visible are the antenufe ; 

 these are only sufficiently preserved to recognize that they are very 

 long and slender, longer than the thorax. The thorax is rather small, 

 quadrate; wings nearly as long as the body, fringed on the costal bor- 

 der as in Palwotlirips fossiUs. The abdomen is composed of only eight 

 joints, but is very long and very tapering, fusiform, the last joint pro- 

 duced, as usual in the j)hysopods ; the third joint is the broadest ; of 

 the wings only the costal border and a part of one of the longitudinal 

 veins can be seen ; there are no remains of legs. Length of body, 2™™.2 ; 

 of antenufe, O^'^.S. ; of head, 0"^^".14. ; of thorax, 0™'^5. ; of abdomen, 

 l°i™.56; greatest breadth of abdomen, O'^^.S. Chagrin Valley, Professor 

 Denton. 



LITHADOTHRIPS, nov. gen. {XcM^, OoUp). 



Allied to Melanotlirips Haliday. The head is large, broad, globose ; 

 the eyes exceedingly large, globose, each occupying, on a superior view, 

 fully one-third of the head ; the antennse very slender, equal, as long as 

 the thorax, the joints eight or nine in number, cylindrical, equal, 

 scarcely enlarging toward their tips. The prothorax is no larger than 

 the head, of equal breadth with it, the whole thorax shaped as in Pa- 

 loeothrips. Only fragments of the wings remain, sufficient to render it 

 probable that they agree well with the character of the group to which 

 Melanotlirips and ^olotlirips belong. The legs resemble those of Pa- 

 loeothrips^ but are slender and apiDcar to be rather profusely supplied 

 with hairs. The abdomen differs considerably in the two specimens 

 referred to this genus. In one it is very broadly fusiform, the tip a little 

 produced, nine joints visible, the apical furnished with a few hairs, 

 and bluntly rounded at the tip ; the other has the sides equal, the apex 

 not at all produced, but very broadly rounded, only seven or eight 

 joints vaguely definable. 



* Proc. Bost. Soc. Nat. Hist., xi, p. 117; Geol.Ma^., v, p. 221. 



