NO. 2337. ]^Ew AMERICAN FOSSIL INSECTS— COCKERELL. 311 



armature of the legs, as the name suggests, is striking. It is a rela- 

 tively small form, with the wings about 7.5 mm. long. The outer 

 side of the discal cell is curved, more or less S-like, an exaggeration 

 of the condition found in the living Glossina fusca. The wings are 

 perfectly clear, the veins very pale. 



The largest of the fossil species is G. oligocena (Scudder), which 

 has the wings about 16 mm. long; next in order is G. vetema; while 

 G. oshorni and G. armatipes are smaller insects, with the wings less 

 than 8 mm. In G. avTnatipes the hind basitarsus carries a pair of 

 stout longitudinally striated spines; similar spines exist in the mod- 

 ern G. fusca. 



Whether Glossina originated in the Eastern or Western Hemi- 

 sphere may be considered doubtful. There are no closely related 

 genera known, and it is a singular thing that no true Muscidae have 

 been found in the Florissant shales. Griinberg (Zool. Anzeiger, 

 1906) described Glossinella schillingsi from East Africa; a genus 

 and species supposed to be allied to Glossina. It is, however, actually 

 very different, with quite different venation. Bezzi in the year fol- 

 lowing stated that Glossinella was not to be separated from Lype- 

 rosia Rondani, which is now known by the earlier name Haematohia. 



EXPLANATION OF PLATES. 



Plate 54. 



Fossil Cockroaches from the PennsylvaniaD. 



Fig. 1. Cobaloblatta simulans. Type X 2. 



2. CohaloMatta simulans. Reverse of type X 2. 



3. Brachymylacris bassleri. Type X 2 . 



4. Phoberohlatta reticulata. Type X 2. 



5. Phthinomylacris pauper. Type X 2. 



6. Atimoblatta flexuosa. Type X 2. 



7. Ptilomylacris medialis. Typo X 2. 



Pl-ATE 55. 



Fossil tsetse fly. Glossina vetema Cockerell. ' 



