CLASS IV. ACARI. 
131 
Genus 1. TROMBIDIUM. Fair., Lair., Leach. 
Legs eight. 
& P- !• From, holosericeum. Subquadrate, blood-red, tomentose; the 
down short composed of cylindric papillae, which arc rounded at 
their extremities. 
trombidinm holosericeum. Fabr., Lair. 
n habits Europe, and is abundant in the spring. 
Genus 2. OCYPETE. Leach. 
Legs six. 
' P- 1 . Ocy. rubra. Red ; back with a few long hairs, the legs with 
many short hairs of a rufous ash-colour ; eyes black brown. 
u °ypete rubra. Leach, Trans. Linn. Sue. xi. 
This curious little animal, which is not larger than a grain of 
s mall sand, is parasitic, and is frequently to be found on the largest 
tipuladous insects, adhering to their legs. No less than sixteen 
specimens have been obtained from one insect. 
j, Fam. II. Gammasidje. Leach, 
dpi porrcct, simple. 
^ Genus 3. GAMMASTTS. Latreille, Leach. 
°% depressed, the skin of the back partly or entirely coriaceous. 
* Anterior portion of the back, and a triangular part behind, cori- 
aceous. 
O 
1. Gamin. Coleoptratorum. Coriaceous parts of the back fuscous ; 
anterior pair of legs a little longer than the hinder ones. 
a mmase des Coleopteres. T.atr. Hist. Nat. des Crust, ct ties Trisect. 
v h. 399. Gammasus Coleoptratorum. Lair. Gen. Crust, ct Insect, i. 
> Gt. '[.each . Acarus Coleoptratorum. Linn., Fubr. 
habits the excrements of horses and oxen, often attaching itself to 
r'carabeei, Hislcrcs, &c. in great numbers. 
§ ** Back entirely coriaceous. 
Gamm. marginatus. Ovate, brown ; belly coriaceous, the sides 
‘. ° ne membranaceous and whitish ; anterior legs nearly twice the 
lJ e hgth of the body. 
a ' J its dung and dead animals. 
*T< 
Fam. III. Acarid.t.. Leach. 
met Jj Urn ^ et ^ w hh mandibles : palpi simple, very short, not por- 
* Genus 4. ORIBITA. Latreille, Leach. 
"V covered by a coriaceous skin; anterior part rostrated; the pro- 
^ Uce d part inclosing the organs of mastication: abdomen subglo- 
S ° Se : hirst witli claws. 
■ Or. gcniculata. Fuscous-castaneous, shining, hairy : legs pale- 
1Sc °us = thighs subclavate. 
