216 THE CANADIAN ENTOMOLOGIST. 



As crassicornis is the type of Arceopus, it is according to Stal clearly 

 also the type of Delphax. D. clavicornis Fabr. is the type of 

 Asiraca Latr., which Stal always called by its correct name; no- 

 where has he called this genus Delphax. Far from having "compli- 

 cated matters," Stal was the first author who set down the correct 

 type of Delphax. Crawford has apparently not seen Stal's Hem. 

 Afr., and what he says seems to be based on wrong second-hand 

 quotations in some obscure paper. He further states, probably 

 relying on the wrong statements of Kirkaldy and Distant, that Stal 

 used Emholophora monoceros Stal as the type of Libiirnia. Had he 

 known Stal's Hem. Afr., he would have seen that Stal maintained 

 Emholophora as subgenerically or sectionally distinct from Liburnia 

 proper. This fact is sufficient to preclude monoceros from the 

 possibility of being considered the type of Liburnia. The type of 

 the latter genus is pellucida Fabr., as pointed out by Van Duzee. 

 Crawford gives good descriptions, and in many cases detail- 

 figures, of the American Delphacids known to him, citing only the 

 the names (with bibliographical references) of the other species, 

 but reproducing the descriptions of the genera which he had not 

 seen. He has, however, overlooked Stal's important work, "Rio 

 Janeiro Hemiptera, H: Homoptera." Of the new genera and 

 species of Delphacidae described by Stal in this work not even the 

 names are mentioned. Delphax cylindricornis Fabr., redescribed 

 from the type by Stal in his "Hemiptera P^abriciana" as Canyra 

 cylindricornis, has also been omitted. From the facts that Craw- 

 ford says this work was published in 1858, and that Delphax 

 seminigra Stal (not "seminegra!") is described on p. 275 of it 

 (whereas the work is from 1869, has only 130 pages, and contains 

 nothing about that species) it is clear that the work is unknown 

 to him. Hygyops pictijrons Stal from the Philippine Islands is 

 cited as a synonym of Delphax pictifrons Stal from Mexico, a 

 synonymy which had been impossible if the author had known 

 the cited papers where these generically distinct species are described . 

 In all Crawford enumerates seven of Stal's publications in his biblio- 

 graphic list, but it seems dubious whether he has seen any of them. 



Stal is the founder of modern hemipterology, and it is not 

 advisable to begin the study of any group of the Homoptera 

 Auchenorhyncha without knowing his works. 



