530 BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



era iu important particulars, which will, perhaps, be increased in num- 

 ber when other specimens permit us to know the peculiarities of the 

 structure of the legs and sternal surface. 



Parolamia rudis. — A single well-preserved specimen (So. 7807) was 

 obtained in the Florissant beds. The elytra are parted and thrust for- 

 ward upon the prothorax, concealing its outer posterior portions ; but 

 this permits the abdomen to be seen, and all other parts which could 

 be seen on a dorsal view are present excepting the legs. The head is 

 nearly smooth, or appears to be slightly scabrous ; the antennae are 

 nearly smooth, the basal joint mesially carinate above, the last joint 

 bluntly pointed. Prothorax subquadrate, a little transverse, the extent 

 of the lateral spines concealed ; surface rather coarsely and pretty uni- 

 formly scabrous. Elytra coarsely granulate at the base, the granula- 

 tions becoming gradually fainter until they disappear, the apical quarter 

 being free, although the surface is not uniform ; outer and inner edge 

 minutely marginate. A fragment of oue of the wings remains, showing 

 that the insect was not apterous. 



Length of body 22.5"™, of head 2,5™", of thorax 4"™, of abdomen 16"™, 

 of antennae 26.5'"", first joint of same 2.5"", its width 1.25"", length of 

 third joint 4.5"", its width at base 0.7"", at tip 0.9"", length of penulti- 

 mate joint 4"", its width at base 0.5"", at tip 0.6"", length of last joint 

 3.25""; width of prothorax, exclusive of spine, 6""'; width of elytron at 

 base 4.5"", in middle 4.25"", at one millimeter from tip 2.5""; length of 

 elytron 14"". 



Hemiptera : Petrolystra {-irpo:;, Lijstra — nora. gen.). 



One of the most striking instances of tropical afiQuities in the Tertiary 

 shales of Florissant is found in the presence of two species of a genus 

 of huge Homoptera, rivaling the famous lantern-fly of South America in 

 size, but differing in neuration and other features from any genus hith- 

 erto described. At first glance one would ^hink it belonged to the 

 Fulgorida, a subfamily which, with Oicadina, includes most of the larger 

 forms of the suborder, and to be somewhat nearly allied to Paralystra / 

 but it differs from this, and so far as I can determine from all Falgorina, 

 in the minuteness of the scutellum, and must be referred instead to the 

 Aphrophorina, although very much larger than any species of that group 

 which I find noticed, while in comparison with the temperate forms of 

 that subfamily it is gigantic, our own largest species not exceeding one- 

 fourth its length. 



The body is robust, the head large, apparently flat above, about twice 

 as broad as long, but considerably narrower than the thorax, the front 

 regularly and very broadly convex ; clypeus about half as broad as the 

 head, somewhat convex, coarsely carinate down the middle with dis- 

 tinct lateral transverse rugse: ocelli indeterminate; rostrum shorter 

 than the breadth of the tegmina. Thorax broadening posteriorly, con- 

 tinuing the curve of the head; the front margin rather deeply and very 



