CLASS V. INSECTA. 303 



cimcns. Mr. Bentley informs me, from observations he made in 

 the summer of 1818, while in Ihimpsliire, liiat the Hippuhoscce are 

 found in a considerably greater abmidance u\\ white and light-co- 

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

 servation was contirmed by the stable-keepers in tli'; vicinity of the 

 Forest. 



Stirps 2. — TT7»?gstwo; the hinder cells complete: thorax anteriorly 

 notched for the reception of the head. 



* Wings of nearly an equal breadth throughout. 



Genus :).53. ORNITIIOMYIA. Latr., Oliv., Leach. 

 Ocelli three, situated in foveolae. 

 Sp. 1. Oruith. avicularia. Leach. 

 Hippobosca avicidaria. Liunt. 

 Inhabits the black grouse and tit-pippit. ^ti/vi^j 



** Wings acuminated. 



Genus .5.59. CRATERINA. Olfers. Stenkpteryx. TA:nch. 

 Ocelli three, situated in foveoke. 



Sp. 1. Cr. Hirundinis. Olfers. Stewpteryx Hirundinis. Leach. 

 Hippobosca Hirundinis. lAnni. 

 Inhabits the nests and bodies of the house-swallow. 



Genus 5C0. OXYPTERUM. Kirhy, Leach. 

 Ocelli none. 



Sp. I. Oxypt. Kirbyanum. Leach. 1'nholnt^ Kt^ln^ 

 Inhabits England. 



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

 the head. 



Genus 501. MELOPHAGUS. Lutr., Leach, O/Jlrs. Melophil.\. 

 Nitzsch. 

 Ocelli none. 



Sp. 1. Mel. ovinns. Latr., Leach. 

 Hippobosca ovina. Linn'c. 

 Inhabits the sheep. 



Fam. 11. Xycteribid.t. Leach. 



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



Genus 562. NYCTERIBIA. L.atr., Leach. Phthiridicm. Her- 

 mann, Olfers. 

 Thorax depressed : mouth situated on the back at the anterior part of 

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

 second long and compressed : tibia with two joints, the first longest 

 and compressed, tlie second joint slender and arcuated : tarsi with 



