REHN AND HEBARD 13 



The features separating Orchelimum from Teratura, Para- 

 xiphidium, Odontoxiphidium , XiphiUinutn and Karniella are very 

 decided and have been previously emphasized, so it seems unnec- 

 essary to discuss them at the present time. 



Erroneously Referred Species. — Aside from the American species 

 here treated, and to which we restrict Orchelirninn, the genus lias 

 been considered by some authors to include two Old World 

 species. The first of these, senegalense Krauss, is certainly 

 distinct generically and we here separate it as a related but well 

 characterized genus ^. Karn}'^ has placed the species Xiphidiuvi 

 bituberculatum Redtenbacher, from Australia, in the genus 

 Orchelimum. This is undoubtedh' not an Orchelimum, as the 

 untoothed cercus shows. Just what its relationship to Con- 

 cephalus {Xiphidium of authors) is, we cannot say, but that the 

 species has no place in Orchelimum is certain. 



Generic Distribution. — From southern Maine, southern Ontario 

 and southern Manitoba (Ashdown) south to southern Florida 

 (Homestead), the Gulf Coast and southern Texas (Bi-ownsville), 

 and in Mexico as far as Orizaba in the eastern part and the state 

 of Jalisco in the west, in the United States west to northern 

 California (Sisson). The genus is apparently absent from the 

 whole desert region of the southwestern United States and also 



2 THYRIDORHOPTRUM new genus {Ovpis window, powrpov tambourine). 

 1877. Orchelimum Krauss (not of Serville), Sitzungsberichte k. Akad. Wis- 

 sensch. Wien, Math. -Nat. CI. Ixxvi, p. 60. 

 Genotype. — Orchelimum senegalense Krauss. 



Related to Orchelimum but differing in the more abbreviate dorsum of the 

 pronotum, which in the male sex has the caudal width subequal to the greatest 

 length, in the very narrow lateral lobes of the pronotum, these in the male 

 sex being distinctly deeper than the greatest length of same, in the extremely 

 large stridulating field of the male tegmina, which has the speculum of great 

 size and in width at least two-thirds that of the whole stridulating field, in the 

 more ample tegmina of the male, the bidentate male cerci, the non-spinose 

 character of the genicular lobes of the cephalic and median femora and in the 

 broad fluting of the lateral faces of the ovipositor abruptly terminating shortly 

 proximad of the apex. 



Only species: 

 Thyridorhoptrum senegalense (Kjauss) 



1877. Orchelimum senegalense Krauss, Ibid., pi. I, figs. 12, 12a. [Bakel, 

 Senegal.] 



We have before us specimens representing both sexes of this interesting 

 genus. 



^ Genera Insectorum, fasc. 135, Conocephalinae, p. 7, (1912). 



TRANS. AM. ENT. SOC, XLI. 



