MISCEIvIyANEA. 

 INSECTS. 



Further Notes on Synonymy in Corethrinae. — The his- 

 tory of Corethra and the allied genera has become somewhat con- 

 fused of late, mainly due to the placing of the t5^pe species of that 

 genus, culiciformis, Degeer, in a genus founded by Loew {Moch- 

 lonyx), for a congeneric species velutina, Ruthe; and partly to the 

 discovery quite recently that a genus Chaoboriis, Lichtenstein, erec- 

 ted in 1800, is synonymous with Sayomyia, Coq., which latter 

 (proposed in 1903) has been adopted of late by the workers in 

 Culicidae in place of Corethra (as applied to those species other than 

 culiciformis and its congeners). 



Corethra was established by Meigen in 1803 for Tipula culici- 

 formis, Degeer ; there can therefore be no argument against this 

 being the type species. Two other species, pallida, Fab. (1781), 

 and plumicornis, Fab. (1794), were added, and it was twenty years 

 after the creation of the genus that a fourth species appeared. 

 This was pimctipennis , Say., followed by flavicans, Mg., in 1830, 

 others being added subsequently. 



Ruthe described velutina as a Corethra * and this species was 

 made the type of Mochlonyx by Loew, When lyoew set up Mochlonyx 

 (in 1844), there were known only four species, culiciformis , plumi- 

 cornis, pallida and fusca, all placed in Corethra. In separating those 

 species with a metatarsus distinctly longer than the 2nd joint from 

 those in which it is several times shorter than the 2nd joint, Loew 

 was morphologically correct, but made the mistake of selecting 

 the wrong group of species for his new genus. 



Now this seems a strange thing for so sound a dipterologist as 

 Loew to do, but if we premise that Loew never actually saw culici- 

 formis, we have an explanation of the whole situation. This is on 

 the assumption that neither Degeer nor any other early writer 

 gave a specification of the relative lengths of the tarsal joints.^ 



In this case Loew would conclude that culiciformis as well as 

 plumicornis, pallida and fusca possessed long metatarsi, and that 

 in velutina, Ruthe, he had found an isolated case to the contrar}^, 

 which he was justified in placing in a new genus. 



• Isis, 1831, p. 1205. As though to complicate matters still further, even 

 Ruthe contradicts himself, for in the two short preliminary diagnoses in I^atin and 

 German he says ist tarsal joint much shorter (the italics are mme) but in the full 

 German description following he says much " longer : " but that this is an error is 

 obvious by the continuation that the fore pair are " shorter still," being only one 

 fourth as long as the 2nd joint, which itself is twice as long as the 3rd. 



i This is a point I have no means of verifying, Degeer's work not being 

 accessible, but Coquillett (Can. Ent., xxx, 189), in establishing Sayomyta, says 

 that the figures are useless for deciding the question. 



