NO. 214G. SOME AMERICAN FOSSIL INSECTS— COCKERELL. 95 



PACHYSOMITES, new genus (Ortalididae). 



A genus of the subfamily Richardiinae, running in Williston's 

 tables ^ exactly to Epiplatea~, but the shape of the discal cell is entirely 

 different, its apical margin being long and very oblique, undulating 

 and forming a gentle double curve, an exaggeration of the condition 

 found in Oedopa; in addition, the first vein extends far toward the 

 end of the wing, reaching the costa at an extremely acute angle, in 

 the manner of the Syrphid genus CMlosla; the submarginal cell is 

 constricted in the subapical region, but expands toward the margin, 

 as in Richardia^ except that the constriction is more pronounced; 

 the first posterior cell is very broad apically, its width even greater 

 than length of oblique end of discal cell; the anterior cross- vein, 

 which is somewhat oblique and gently arched outward, is far before 

 the middle of discal cell. The second basal cell is very narrow, and 

 the anal is retracted, its lower angle a very wide one, as in Richardia. 

 Robust ; femora unarmed and not 

 incrassate; wings with no con- 

 spicuous markings; ovipositor 

 short. 



PACHYSOMITES INERMIS. new species. 



Length 8.3 mm. ; very robust ; 

 thorax black; dorsallv bare; legs 

 dark brown, unarmed^ femora not ''''' 4.-rACHysoMiTEs inermis. apex of 

 incrassate; abdomen thick, about 



3.8 mm. long, dark reddish, with an appearance of longitudinal 

 banding which seems to be due only to the condition of preservation; 

 ovipositor short and thick, about 1 mm. long. Wings about 5.5 mm. 

 long, hyaline, without bands or spots, except a dark cloud above end 

 of first vein, such as occurs in Euxesta and Pseudeuxesta. The fol- 

 lowing measurements are in microns: 



Marginal cell on costa, about 1040 



(It is impossible to be exact, as the first vein grades gradually into 

 costa at end.) 



Submarginal cell on wing-margin, not allowing for curve 770 



(The costa is thickened and minutely bristly, the thickened part ex- 

 tending as far as end of third vein.) 



Diameter of submarginal in middle of constriction 288 



Diameter of submarginal cell where expanded, basad of constriction 464 



Submarginal cell on first basal 1056 



Length of anterior cross-vein 3-52 



First posterior cell on wing-margin, not allowing for curve 1280 



Fourth vein beyond discal cell, about 720 



Oblique apical side of discal cell 1120 



Discal cell on first posterior 1712 



1 N. Amer. Diptera, third edition. 



