NO. 2210, FOSSIL 1^'SECTS FROM FLORISSA'ST— -COCKE RELL. 391 



NEUROPTERA. 



INOCELLIA TUMULATA Scudder. 



A specimen collected at Florissant (Miocene shales) by Mr, George 

 Wilson shows the ovipositor, which is about 6 mm. long. The an- 

 terior wings are 9,5 mm. long; the venation agrees in the main with 

 Scudder's figure, but there are some differences, partly to be ascribed 

 to variation and partly, I think, to error in Scudder's figure. The 

 principal difference is that the cell in the first fork of the radial 

 sector is relatively short, closed before the base of the cell in the 

 fork of the upper branchlet. 



HEMIPTERA. 



METROBATES AETERNALIS Scudder. 



A specimen from Florissant (George Wilson) shows the antennae, 

 not described by Scudder. They are quite long and 175 \i thick 

 near the base. The eyes are prominent. 



DIPTERA. 



PLECIA DECAPITATA, new species (Bibionidae) . 



Length about 10.5 mm.; thorax and legs dark; wings duskj' but 

 not very dark, the costal region not darker than the rest; abdomen 

 2.4 mm. wide, dark brown with narrow hyaline sutural bands, which 

 are less than half as wide as the alternating dark ones. Separation 

 of third vein from first about 3 mm. from base of wing and 5 from 

 apex, the wings being 8 mm. long. The following measurements 

 are in microns : Separation of third vein to anterior cross-vein about 

 1,600; depth of marginal cell at level of cross- vein, 480; origin of 

 third vein to its fork (in a straight line), 2,560; end of first vein to 

 end of second (upper branch of third), 720; end of first vein to end 

 of lower branch of third, 2,240; depth of submarginal cell at level 

 of end of second vein, 368. 



Miocene shales of Florissant (George Wilson). 



Eoloty'pe.—Q^X. No. 63458, U.S.N.M. 



This may be separated from the previously known species of Plecia 

 from Florissant as follows: 



Small, wing 6 mm. long melanderi Cockerell, 



Larger, wing 8 mm. or over 1. 



1. Wing long and narrow ; marginal coll narrow, its greatest depth less than 



400 M- exi)lanata Cockerell. 



Wing, ordinary ; marginal cell broader, its greatest depth over 450 n 2. 



2. Abdomen with the light bauds wider than the dark ; submarginal cell 



broader axeliona Cockerell. 



Abdomen with the dark bauds much wider than the light ; submarginal cell 

 narrower decapitata Cockerell. 



