384 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 52. 



less (95 At) than distance from lower end of first transversocubital to 

 insertion of first recurrent (128 n), — a character of Heriades proper 

 as against Chelostonia; second recurrent nervure with an even, gentle 

 outward curve; lower end of basal nervure curved, and the transverso- 

 raedian (which is 400 ij. long) in a straight line with it, its upper part 

 vertical, but the lower end curved basad, as is characteristic of Heria- 

 dines. The following measurements are in microns: Width (depth) 

 of stigma, 160; width (depth) of marginal cell, 368; marginal cell on 

 first submarginal, 320, and on second, 448; total length of second 

 submarginal cell, 850; first submarginal cell on basal nervure, about 

 288, and on first discoidal cell, 816; second submarginal ceU on third 

 discoidal, 672; basal nervure on first discoidal ceD (not allowing for 

 curve), 752. 



Florissant, in the Miocene shales. The largest Florissant Heriades. 



Type.— C&t. No. 62543, U.S.N.M. 



EXPLANATION OF PLATE 31. 



Fig. 1. Tipula gardneri, new species. Oligocene, Gurnet Bay, Isle of Wight. 



2. Riphidia brodiei, new species. Discal cell and adjacent parts. Oligocene, 



Gurnet Bay, Isle of Wight. 



3. Mongoma cruciferella, new species. Oligocene, Gurnet Bay, Isle of Wight. 



4. Bibio gumetensis, new species. OUgocene, Gurnet Bay, Isle of Wight. 



5. Bibio oligocenus, new species. Oligocene, Gurnet Bay, Isle of Wight. 



6. Acreotrichites scopulicomis, new species. Antenna. Miocene (Florissant), 



Florissant, Colorado. 



7. Mesomyites concinnm, new species. Oligocene, Gurnet Bay, Isle of Wight. 



8. Rhamphomyia hypolitha, new species. Miocene (Florissant), Florissant, Col- 



orado. 

 Figs. 9, 10. Urorlalis caudatus, new species. 10. Discal cell and adjacent parts. 



Miocene (Florissant), Florissant, Colorado. 

 Fig. 11. Protoscinis perparvus, new species. Discal cell and adjacent parts. Oligo- 

 cene, Gurnet Bay, Isle of Wight. 



12. Aeolothrips brodiei, new species. Oligocene, Gurnet Bay, Isle of Wight. 



13. Sisyra (?) disrupta, new species. Oligocene, Gurnet Bay, Isle of Wight. 



14. Taeniuritesfortis, new Bpecies. Lanceolate cell, etc., of anterior wing. Mio- 



cene (Florissant), Florissant, Colorado. 



