MODERN SYSTEM. 
130 
Aranea scenica. Linn., Fabr. Atte pare. T Valck. Salticus scenicu?. 
Latr., Leach. 
Inhabits walls and palings. It is found in most parts oi Europe, and is 
called in Britain the Hunting Spider. 
Genus 23. ATTUS. Watch., Leach's Supp. to Encycl. Brit. Sae- 
ticus. Latr., Leach’s Edin. Encycl. vol. vii. 
Maxilla straight, longitudinal, subrhomboidal or inversely cuneate- 
ovate: lip elongate, suboval, with the apex obtuse: palpi filiform: 
thorax elongate, narrow, subconic : eyes disposed in the form ot a 
horse-shoe; the two middle eyes largest: legs slender, elongate, the 
first pair thickest and not longer than the fourth pair; the second 
and third pairs of nearly an equal length and shorter than the other 
pairs. 
Sp. 1. Att.for/nicarius. Thorax anteriorly black, behind red : abdomen 
fuscous, with a white spot on each side : legs red. 
Attus formicarius. Watch. Salticus formicarius. Latr., Leach. Arab 
gnee fourmi. De Geer. 
Inhabits Europe, residing on plants and walls. It is very rare in Scot- 
land, and lias not been observed in England. 
Class IV. AC A JR I. Leach’s MSS. 
In the Supplement to Encycl. Brit. vol. i. the animals of this Class 
were arranged with the Arachnoida and formed the Order Monomcro- 
somata. Since that paper was written, Dr. Leach has, horn a further 
investigation of their characters, separated them from the Arachnoid:* 
(in which they differ essentially), and considers them as a distinct 
class ; they are for the most part parasitic, living on the bodies ol 
other animals : to the lovers of the microscope these animals will id- 
ford an extensive field for their research and investigation; they are 
very numerous, highly interesting, and as yet but imperfectly known- 
Character. — Body formed but of one segment : mouth rostrifonu, 
or in some furnished with maxillse and mandibles : legs six or eight •' 
trachea for respiration. 
Section I . — Legs formed for walking. 
A. Mouth with mandibles. 
Earn. I. Trombidiam. Leach. 
Palpi porrect, and furnished at their extremities with a moveable ap' 
pendage. Eyes two, placed on a pillar. Body apparently divide 1 
into two parts by a transverse line; the anterior division bearing 1 1 
eyes, mouth, and four anterior legs, 
