FOSSIL ORTHOPTERA FROM THE ROCKY MOUNTAIN TERTIARIES. 



By Samuel H. Scudder. 



Homixogamia ventt iosiis. — The remains upon which ihis species is based, 

 consist of the apical portion of the ventral surface of a cockroach's 

 abdomen found by Mr. T. L. Mead at Castello's ranch, South Park, 

 Colorado. Five segments are seen in natural juxtaposition, showing 

 that the apical i^ortion of the abdomen was very regularly rounded, 

 almost exactly semicircular ; the terminal segment presenting no break 

 in the regular continuity of the curve. This segment was ample, broader 

 than long, and probably neither veiy tumid nor greatly keeled ; for in 

 the present perfectly flattened condition of the fossil there is neither 

 break nor folding of the integument ; the two segments following this 

 are very strongly arched (the penultimate being semicircular) and 

 greatly contracted at the middle, so that this portion is not less than 

 half as long as the lateral parts ; the anterior border of the antepenul- 

 timate segment is straight along the middle; the segment anterior to 

 this is also arched, though not strongly, is oppositely sinuate (as are, to 

 a less extent, the segments posterior to it), and also much contracted in 

 the middle, so as to be less than half as long as at the sides; while its 

 predecessor is slightly arcuate in the opposite direction (probably 

 exactly transverse in life), and equal or subequal throughout. All the 

 segments are uniformly, rather abundant!}', and very delicatel}' granu- 

 late throughout. There is no trace of cerci, but the place where they 

 should occur is too broken to assert that they did not exist externally; 

 still the conformation of this region would lead one to suppose that they 

 must have been excessively minute, and perhaps altogether concealed 

 within the segments, as in Cryptocercus Scudd. 



Length of fragment, 8'""'; width of same, 12.25'"'"^; length of term- 

 inal segment, S-G""*^; width of same, 6.3™"^; length of antepenultimate 

 segment in the middle, 0.6"^"^ ; at the sides, l.SS^"". 



I have referred this species to Romoeogamia with some doubt; on 

 some accounts, it would seem to be more nearly allied to Polyphaga, but, 

 as the specimen is too fragmentary to allow of more exact determina- 

 tion, I have preferred to place it in the Kew World genus, rather than 

 in its close ally, which is restricted to the Old World ; possibly it should 

 be referred to neither, but to a new group. 



A great many fossil cockroaches have been found, mostly in the Car- 

 boniferous formation. Kearly all are described from tegmina. Only a 

 few species have been discovered in the Tertiaries ; and one of these, 

 found in Parschlug in Steiermark, has been referred by Heer* to Hetero- 

 gamia, a name used to include both Poh/phaga atid Romoeogamia. 



Lahidura tertiaria. — A single fairly-preserved specimen (No. 1725) was 

 found near Castello's ranch, South Park, Colorado, by Mr. Jesse Ran- 

 dall, and brought home by the United States Geological Survey of the 

 Territories. The specimen is a female, as shown by the number of the 

 abdominal segments. The head, which is badly preserved, is of about 

 equal length and breadth behind the labrum, so that as a whole it is 



'Heer, Insekt.Fauiia Oeuiug. ii, 1, pi. 1, fig. 1. 



