32 THE ENTOMOLOGIST. 



THE FOSSIL ORTHOPTERA OF FLORISSANT, 



COLORADO. 



By T. D. a. Cockerell. 



Orthoptera are uncommon in the Tertiary rocks, and 

 usually poorly preserved, although they must have abounded in 

 former times as now. Probably most of the species were better 

 able to escape destruction during volcanic eruptions than 

 smaller and more fragile insects. The Miocene shales of Floris- 

 sant have yielded no fewer than thirty-three species, and although 

 this must be but a small fragment of the Orthopterous fauna of 

 that time, it is sufficient to give us some idea of the types exist- 

 ing perhaps a million years ago. Two new species have been 

 recently discovered by Professor Wickham, and are described 

 below. 



The Forficulidae are represented at Florissant by the extinct 

 genus Lahiduromma, Scudder, with no fewer than ten species. 

 Earwigs are the only Orthoptera in the shales which can be 

 called common. 



Blattidse are represented by three genera still living in 

 America, each with a single species. It is possible that the 

 species referred to Zetobora is really an Ischnoptera, and iden- 

 tical with the described member of that genus. 



The Mantidae are represented by three species, referred to 

 two genera, both believed to be extinct. Scudder has described 

 one Phasmid, placing it in Agathemera, a neotropical genus still 

 extant. In the Acridiidgs we find the apparently extinct genus 

 Tceniopodites, Ckll. of the Acridiinae; three species of (Edipodinse; 

 and three of Tryxalinse. All these Acridians, whenever their 

 generic characters can be made out, seem to belong to extinct 

 genera. In the Locustidse we have Palceorehnia, Ckll., a remark- 

 able extinct genus referred to Phaneropterinae ; a very dubious 

 member of the Pseudophyllinffi ; Lithymnetes, Scudd., an extinct 

 genus placed in the Oriental and Australian group Phyllo- 

 pharinae ; a Conocephaline referred to the living genus Orcheli- 

 mum ; two Decticinae, belonging to the living genera Capnohotes 

 and Anahrus ; and two species of the widely distributed Gryll- 

 acris, of the subfamily Gryllacridinae (Gryllacrinae, Kirby, 

 Scudder). 



As the list stands, less than a third of the species seem to 

 belong to modern genera, and it is quite possible that if we had 

 complete specimens of these, at least some of them would prove 

 to be incorrectly assigned. On the other hand, it may be that 

 some of the genera described as extinct are still living. The 

 whole matter must stand subject to future revision, should 

 better materials be brought to light ; but we can at least say 

 this, that the Miocene Orthoptera of Colorado were, on the 



