Mr, ClarkV Observations on the Genus Oefirus. 321 



Remarks on the generic and Specific Characters of the Oestri. 



The characters which diftinguifh this genus have been defcribed 

 fo very oppofitely by various writers, that I cannot well conclude 

 this paper without taking fome notice of thefe alfo ; and having 

 many fpecimens of them in my pofleiiion 1 was induced to difleel 

 them for this purpofe. The refult of the enquirv has been the dif- 

 covery of characters confiderably different from thofe which have- 

 hitherto been afligned them. 



The excellent Scopo!/\ confeious of the obfeurity of this genus, 

 has altogether omitted giving any account of them in the Entoino- 

 logia Carniolica. 



And if we except. the miftake of the CE. Equi for Bovis > the cleared 

 and beft account of the fpecies is ftill to be feen in Linnceus. 



Fabricius, in his Species Irtfedtorum * 9 has nearly copied the Lin- 

 noean account of the Ocftri ; but in a fubfequent work of this au- 

 thor, the Mantijfa Inferior um t, a fpecies under the title of Equi is 

 introduced, and the fpecies CE. htvmorrhoidalis and veterinus are con- 

 fidered as varieties a and /5 ! while the error relating to the true 

 Equi is continued under the name of Bovis. 



The mod extenfive enumeration of the fpecies of this sen us mav 

 be feen in Profeffor Gmelin's J new edition of the Sjjfema Nature? ; 

 but the errors relating to the fpecies have been in that work con- 

 fiderably increafed. Inftead of placing the Equi in the name of 

 Bovis, as his excellent original had done, we find the ■h.rtmrrhoidalis ; . 

 and by placing the Equi again in the name of ha?morrhoidaiis, 

 and mixing; the references to each, an almoft inextricable labv- 

 rinth of confufion is the confequence, while the true Bovis ftill 

 efcapes undefcribed, unlefs as being the fame as hemorrhoidalis. 



* Species Infeclorum, vol. ii. p. 398. -j- Manhjfa In/ffibtidtn, vol. ii. p. 321. 



| Gmelin, Syjl. Nat. par, iv. p. 2810. 



Vol.. III. T.t The 



