CLASS V. IXSECTA. 303 



cimens. Mr. Bentley informs me, from obser%'ations he made in 

 the summer of 1818, while in Hampshire, that the Hippobosca: are 

 found in a considerably greater abundance on white and light-co- 

 loured horses than tliose of a black and dark colour; and this ob- 

 servation was contirmcd by the stable-keepers in the vicinity of the 

 Forest. 



Stiups 2. — Tr*«^stwo; the hinder cells complete: thora.v anteriorly 

 notched for the reception of the head. 



* Wings of nearly an equal breadth throughout. 



Genus 553. ORNITHO:\IYlA. Latr., Oliv., Leach. 

 Ocelli three, situated in foveolae. 

 Sp. 1. Ornilh. uviculuria. Leach, 

 Hippobosca avicularia. Linnc. 

 Inhabits the black grouse and tit-pippit. 



** Wings acuminated. 



Genus 559. CRATERINA. Olfers. Stesepteryx. Leach. 

 Ocelli three, situated in foveol<e. 



Sp. 1. CV. Hirunditus. Olfers. Stenepteryx Hirundinis. Leach, 

 flippobosca Hirundinis. Linnc. 

 Inhabits the nests and bodies of the house-swalIo\'r. 



Genus 560. OXYPTERUiM. Kirby, Leach. 

 Ocelli none. 



■Sp. 1. Oxypt. Kirhyanum. Leach. 

 Inhabits England. 



Stirps 3. — Wings none : thorax anteriorly notched for the reception of 

 the head. 



Genus 501. MELOPHAGUS. iMtr., Leach, Olfers. Melopuila. 



J\'itS:9ch. 

 Ocelli none. 



Sp. 1. Mel. ovi7ius. Latr., Leach. 

 Hippobosca ovina. Linjte. 

 Inhabits the sheep. 



Fam. II. NvcTERiBid. Leach. 



Head united with the thorax : nails of the tarsi simple didactyle. 



Genus 562. NYCTEPtlBIA. Latr., Leach. Phthiridium, Her- 



niann, Olfers. 



Thcyrat depressed : mouth situated on die back at the anterior part of 



tlie thorax : legs six, placed at the sides ; femora witli two joints, the 



second long and compressed : tibice with two Joints, the first longest 



and compressed; the second joint slender and arcuated : tar^l with 



