CLASS V. INSECTA. 
303 
cimens. Mr. Bentley informs me, from observations he made in 
the summer of 1818, while in Hampshire, that the Ilippobosca are 
found in a considerably greafer abundance on white and light-co- 
loured horses than those of. a black and dark colour ; and this ob- 
servation was conlirmed'b'y the stable-keepers in the vicinity of the 
Forest. 
Stirps 2. — Wings two ; the hinder cells complete: thorax anteriorly 
notched for the reception of the head. 
* Wings of nearly an equal breadth throughout. 
Genus 553. ORNITHOMYIA. Lair., Oliv., Leach, 
Ocelli three, situated in foveolje. 
■Sp. 1. Ornith. avkularia. Leach. 
Hippobosca avicularia. . Lime. 
inhabits the black grouse and tit-pippit. 
** Wings acuminated. 
. Genus 559. CRATERINA. O/fers. Steneptep.yx. Leacli. 
Ocelli three, situated in foveol®. 
Sp. 1. Cr. Hirundinis. Olfers. Stenepteryx Hirundinis. Leach. 
Hippobosca Hirundinis. Linni. 
Inhabits the nests and bodies of the house-swallow. 
Genus 560. OXYPTERUM. Kirby, Leach. 
Ocelli none. 
Sp. 1. Qxypt. Kirbyanum. Leach. 
Inhabits England. 
Stirps 3. — Wings none : thorax anteriorly notched for the reception of 
the head. 
Genus 561. MELOPHAGUS. Latr., Leach, Olfers. Melophila, 
’ Nitzsch. 
Ocelli, none. 
®p. 1. Mel. ovinus. Latr., Leach. 
Hippobosca ovina. Linnc. 
Inhabits the sheep. 
Earn. II. Nycteribiiue. Leach . 
Head united with the thorax : nails of the tarsi simple didaclyle. 
Genus 562. NYCTERIBIA. Latr., Leach. Phtiiiridiu.m. 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, the second joint slender and arcuated : tarsi with 
