HEMII'TERA HETEROPTERA LYG.EID.E. 4(Jl 



PACHYMERUS PETRENSIS. 



I'l. 5, Figs. 7(>, 71. 

 Pachi/merus petrenxiti Scudd.. Bull. U. S. Geol. Geogr. Surv. Terr., Ill, 7G1 (1*77). 



A single specimen, of which most of the right half i.s destroyed, repre- 

 sents this species, which is placed here provisionally, principally because it 

 appears to be closely related to fossil species put in this group by lleer. 

 It seems to be a larva, and to belong to the Myodochina in the vicinity of 

 Eremocoris. The outline of the head is vague and broken, but the front is 

 apparently bent at a right, angle. The antennae are about half as long as 

 the body, four-jointed ; the basal joint only about half as long again as 

 broad, the others subequal, very slightly smaller at the base than at the 

 apex, but otherwise equal, the second a very little the longest, the last 

 pointed at the tip. Thorax and abdomen of about equal length, the former 

 equally broad throughout (or nearly so) ; the fore and middle femora short 

 and stout, about as long as their separation from each other. Abdomen 

 expanding suddenly at the base, so that the second segment is broadest and 

 apparently half as broad again as the thorax, beyond tapering rather rap- 

 idly to a rounded tip. 



Length of body, 3 mm ; antenna?, 1.5"""; fore femora, 0.35 mm . 



Fossil Canon, White River, Utah. One specimen (W. Denton). 



If). TIROMERUS gen. nov. (refpto, 



Head broadly triangular, as broad as front of thorax, the front angularly 

 rounded, the eyes basal ; antennae much more than half as long as the body, 

 the first joint distinctly surpassing the head, the second very slender and 

 almost as long as the third and fourth together, these subequal, the last 

 slightly incrassated. Thorax transverse, trapezoidal, tapering gently, the 

 sides more cr less but not much ampliated, with no distinct division into 

 anterior and posterior lobes. Ilemelytra with the corium barely reaching 

 the middle of the abdomen. 



The genus appears to be allied to Rhyparochromus, but the relative 

 length of tlu second joint of the antenna' separates it from any existing 

 genus with which it appears comparable. Two species are found at Flor- 

 issant, which may perhaps be generically distinct, in which case T. torpefactus 

 should be regarded as typical. 



Tablt- o/" the Kpci'ic* of Tirontfru*. 

 Thorax much lens than twirn an hrond a.s long ..................................... 1. T. torpr/actHf. 



Thorax fully twice a,s liroad n long ................................................... i T. takillHMii. 



VOL XIII - L'fi 



