CLASS III. ARACHN01DA. 
119 
Fam. II. Scokpioniwe. Leach. 
Palpi arm-shaped. Mandibles didactyle. I^egs alike. 
The animals composing this Family constitute a most natural 
groupe. 
St i rps 1 . — Tail none. F.yes two, or four. Pccten none. 
« The ocelli of the animals of this division arc placed on the sides 
of the anterior segment of the body or thorax. ’! hey want the tail 
and the pect inated processes near the base of the abdomen, by which 
they may very easily be distinguished from those of the second Stirps, 
with which they w re formerly arranged by FubriciuS under the title 
Scorpio. Two species only were known to Linne, who referred them 
to his artificial genus PhaUmgmm. The greater number of the spe- 
cies live beneath the bark of decaying trees or under stones; but one 
»t least is parasitical, and attaches itself to the legs of flies.” Leacltls 
Zool. Misc. vol. iii. Those genera of the second Stirps include the 
Scorpion, ike. 
Genus 2. OBISIUM. Illigcr, Leach. 
Pody cylindric : thorax composed of one segment: mandibles porrect 
eyes four. 
Sp. l. Obi. trombidioides. Second joint of the arms elongate: tingers 
long and straight. 
Inhabits France and England, under stones. 
A valuable Monograph has been published on the British species 
of this and tic following genus in the third volume of the Zoological 
Miscellany, and is illustrated with very accurate figures of the whole. 
Genus 3. CIIELIFEIl. Geoff., Leach. 
Thorax composed of three parts : mandibles short : eyes two. 
S P- 1. Ch.fasda.lus. Hands oval; segments of the abdomen bordered 
with whitish. 
I -helifer fasciatus. Leach, Trans. Linn. Soc. ix. 
Inhabits beneath the bark of willow and other trees. 
Obs. — O f the second stirps there are no British genera. 
Order II. DIMEItOSOMATA. Leach. 
Fam. I. Pualaxgid/e. Leach. 
Lyes two : anus simple. 
Genus 4. PIIALANGIUM of authors. 
Lyes placed in a common peduncle : mandibles corneous, subcvlindric, 
compressed, Inarticulate, indexed or geniculated at the second joint. 
