Mr. Ci^ARK'j Olifervatiom on the Getius Oejlrus. 2gi 



all the fpecics in one view in their various ftates, taken from the 

 fubjedls thcmfelves; and this will be the more ufefui and necel- 

 fary, as hardly any of the /anw, or perfctSt infedts, have ever yet 

 been intelligibly figured. 



The obfcure and fingular habitations of the Britifli Oe/ln are the 

 ftomach and inteftines of the horfe, the frontal and maxillary 

 finufes of the flieep, and beneath the fkin of tke backs of horned 

 cattle. In other parts of the world they inhabit various other 

 animals ; but our prefent enquiry is neceflarily limited to thofe of 

 our own country, which includes all thofe about which any dif-" 

 ficuity or obfcurity has arifen. 



Of the Oestrus Bovis. 



This rare fpecies has been entirely omitted by Linnaeus, and 

 appears to have been unknown to nearly all the later writers on 

 Natural Hiftory, who, inftead of the true CE. Bovis, have defcribcd 

 a fpecies pecuhar to the horfe under that name. Linnaeus imagined 

 alfo that it was the fame fpecies which inhabited both the ftomachs 

 of horfes and the backs of oxen*, which certainly never happens. 



The larva, tab. 23, fig. i , taken from the back of the cow, is fo 

 unlike the other larva; of this genus, that I did not imagine, till I 

 procured the fly from it, that it was the larva of an Otjlrus. It 

 does not poflefs t\it aculely the marginal y^/rf", or the lips, which are 

 the prominent charafters of the larva of the CE. Equi and hamor- 

 rkoidalis. 



It lives beneath the Ikin, being fituated between it and the cel- 

 lular membrane, in a proper fack or abfcefs, which is rather larger 

 than the infed, and by narrowing upwards opens externally to the 

 air by a fmall aperture. . £i 



* Habitat in ventriculo equorom, in bourn doifo. L\nn. S^ll, Nat. 2. p. ^6g. ed- diiojccimt. 



P p 2 When 



