41G 



C It U STACEOLO G Y. 



Arschni 

 d«s. 



•_'". EaYTH- 

 R.TiUS. 



Phihnj 



aide-. 



21, TROM- 

 BIDIUM. 



Tlncto. 

 rium. 



Holoseri. 

 eeum. 



Fu'.igino- 



iU'H. 



and Fabricius may be referred to this family. I have 

 not examined the speeies with sufficient attention, the 

 following list I therefore give with doubt, viz. 'Trom- 

 bidium. I. Trimaculatum. 2. Miniatum. 3. Parieti- 

 num, (Acorns baccarum, Linn.?) 4>. Congencricum. 

 5. L/ipidum. 6. Tclarium. 7. Sociale of Hermann. 

 Trombidium trirna,eulatum is figured by Rossi. Acnrus 

 Hirundinis, and Vespcrtilionis seem to form a distinct 

 genus." 



B. A moveable appendage at the extremity of the 

 palpi. 



Genus XX. Eryturmvs, Lair. Acarus, De Geer. 

 Trombidium, Hcrm. 



Eyes two, sessile. 



Palpi elongate and conic; the under part of the last 

 joint armed with a chelate moveable appendage. 



Bod'/ entire ; the division between the two anterior 

 pair, and posterior pair, not very remarkable. 



Sn. 1. Fhalangioides. Feet very long, the last joint 

 broad and compressed ; the hinder, and then the ante- 

 rior, longest ; body obscurely red, with a yellowish 

 orange band. 



Trombidium phulaugioides. Hermann. 



Erylhrawi phalangioides. Latreille. 



Inhabits the ground, running with rapidity ; is found 

 throughout the greater part of Europe; found by Mr 

 Leach at Swansea. 



Genus XXI. Trombidium, Fabr. Oliv. Lain. Lair. 

 Horn. Acarus, Linn. 



Eyes four, two on each side, pedunculated. 



Palpi elongate-conic, inserted at the base of the pos- 

 terior sides of the lip ; consisting of four joints, the first 

 very short, the second larger than the third, the last 

 conic; the point (at least) horny, nail-shaped, acute ; the 

 base with a moveable cylindrical appendage. 



Body divided into two parts ; the anterior part tho- 

 racic, stronger and narrower, bearing the mouth, eyes, 

 and four anterior feet ; the posterior part abdominal, 

 broader, very soft, bearing the four posterior feet, 

 which are at a notable distance from the others. 



Observe. Besides the above character, which is es- 

 sential, we may subjoin the following. Mandibular two, 

 compressed and horny, incurved at their base. Lip 

 (labium) membranaceous, somewhat conic, sheathing 

 the mandibulae. Feet six, jointed, with two very short 

 nails, which are compressed and arched, being conceal- 

 ed in a fissure in the middle of the apex of the tarsus ; 

 the anterior ones generally longest. 



Sp. 1. Tinctorium. Body somewhat quadrate; blood 

 red, immaculate, and covered by a velvety down ; the 

 hairs setaceous, elongate, and bearded. 



Acarus linctorius, Linne. 



Trombidium tinctorium, Fabr. Herm. Latr. 



Inhabits Guinea; is often preserved amongst collec- 

 tions of insects from that place, whence we infer it is 

 not an uncommon species. Its colour is destroyed by 

 alcohol. 



Sp. 2. Holosericcum. Body somewhat quadrate ; 

 blood red, without spots, and tomentose; the down 

 short, composed of hairs, or cylindrical papilla?, round- 

 ed or obtuse at their points. 



Inhabits Europe ; common, in the spring, on walls 

 and trees in gardens. It is the Acarus holosericeus of 

 Linne ; Trombidium holosericcum of Fabricius, Her- 

 mann, and Latreille. 



Sp. 3. Fuliginosum. Body elongate-quadrate, of an 

 immaculate obscure red colour, and tomentose; the 

 down short, with bearded hairs. 



Trombidium fuliginosum, Hermann, Latreille. 



Family VIII. Phalantcudes. 



Arachni- 

 ds. 



I. Eyes not placed on a common peduncle, but at " ""T-" 

 some distance from each other. 



Genus XXII. Siro, Latreille. 22, gj,, . 



Mouth naked, with two mandibules, which are dou- 

 ble-jointed, cylindrical, and compressed, with their 

 points armed with forceps placed between two long 

 narrow maxilla?, which are marginated on their inner 

 edge. 



Palpi two, composed of five elongate joints, the se- 

 cond the longest. 



Body oval. 



Eyes two in number, situated on the sides of the 

 thorax, on an erect tubercle, at a distance from one an- 

 other. 



Abdomen annulated above and below. 



Feet elongate and filiform ; the tibiae and tarsi con- 

 sisting of two joints ; the last larger and clavate, "being 

 armed with a bent nail. 



Sp. 1. Rubens. Pale red; feet lighter coloured. Rubens. 



Siro rubens, Latreille. 



Inhabits France, harbouring under moss at the roots 

 of trees. Length about a line. 



Genus XXlll. Trogulus, Latr. Phalangium, Linn. 23. Trogu 

 Fabr. tus » 



Mouth situated in a cavity under the anterior part of 

 the thorax, furnished with two mandibulae, palpi, and 

 maxilla?. 



Mandibles cylindrical, elongate, compressed, double- 

 jointed and kneed, the last joint armed with a forceps, 

 and nearly equal chela?. 



Palpi filiform, a little longer than the mandibula?, in- 

 serted at the internal lateral base of the maxilla?, and 

 consisting of five joints ; the first very short ; the second 

 very long and cylindrical ; the third and fourth of a 

 moderate and nearly equal length, of a cylindrico-coni- 

 cal form, the fourth a little longer ; the last cylindrical, 

 inclining to oval, armed at the apex with a very minute 

 horny nail. 



Maxilla? somewhat horny, oval, spoon-shaped, mar- 

 ginated, and divaricating. 



Lip-like body ; at the angle of separation small, mem- 

 branaceous, and nearly round; seemingly formed of 

 two moon-shaped parts joining together, the interme- 

 diate space receiving the apex of the chelae. 



Body ovate-elliptical, depressed, marginated in front, 

 rounded at the apex. 



Eyes two, placed at a short distance from one an- 

 other on the back, the insertion scarcely prominent. 



Feet eight, elongate, filiform, each arising from a com- 

 mon base separate from the pectus ; the second and 

 fourth pair longest, and of nearly an equal length ; 

 next the third, then the first : The tibia? and cona? con- 

 sisting of two, the tarsi of three joints ; the first joint 

 of the latter, and then the last, longest; last joint of 

 tarsus armed with a nail. 



Sp. 1. Nepceformis. Obscure-cinereous, or brown- Ncpafor- 

 ish ; the dorsum and sides of the abdomen obscurely mis. 

 carinated ; the external apex of the first joint of the 

 tarsi lengthened. 



Phalangium tricarinatum, Linne. 



Phalangium carinatum, Fabricius. „ 



Acarus nepceformis, Scopoli. 



Trogulus nepceformis, Latreille. 



Inhabits France and Germany, lurking under stones. 

 It has not hitherto occurred in this country. 



J I. Eyes placed on a common peduncle, very close to- 

 gether. 



