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tapering; first, short; second, third, and fourth, equal; fifth equal- 

 ling second, third and fourth conjoined; terminating in a filament; 

 perfectly free from hairs or spines. Coxgb of cephalothoracic segments 

 well marked. Segments of cephalothorax : first, much broader than 

 head, second and third gradually broader ; third and fourth equal ; 

 fifth, sixth, an^ seventh gradually decreasing in breadth; seventh 

 as broad as first. Posterior margin of first three rings convex down- 

 wards; fourth and fifth, median portion convex downwards, coxae 

 concave upwards ; sixth and seventh rings concave downwards, 

 their coxae quadrilateral, strongly angular, suture well marked; 

 coxae of the seventh extending half-way down fourth abdominal 

 ring ; raised transverse border along margin of each ring ; a bor- 

 der of small spines along lateral edges of coxae (visible under J inch 

 power). Abdominal segments: first, semilunar, very linear, coxae nearly 

 obsolete, covered by those of seventh cephalothoracic segment : second, 

 linear, coxae rounded, uncovered by seventh cephalothoracic ring; third, 

 fourth, and fifth, each equal in breadth to first and second conjoined; 

 coxae well marked and curved, inferior border of entire segment con- 

 vex medianly and deeply concave externally, so as to form a projecting 

 angle, gradually decreasing in breadth from third downwards ; terminal 

 ring deeply concave over insertion of last false feet, the segment being 

 here linear, coxae nearly obsolete, medianly produced, truncately trian- 

 gular, apex deeply emarginate ; total length of ring about twice that of 

 fifth ; the rings gradually increase in length from one to six. Abdo- 

 minal false feet: last pair uncovered, articulated in excavated posterior 

 margin of last ring. Peduncle, and ischium, and accessory filament, as 

 in genus, q. v. 



Colour : uniform red brown, without spots or marbling, though va- 

 rieties may occur. 



Habits : runs with agility, as conveyed in the name ; buries itself 

 deep in the ground, and generally congregates in numbers ; very impa- 

 tient of dryness, soon dying on exposure to air. 



Habitat : very moist places, amongst all kinds of decaying matter ; 

 also amongst moist dead leaves, amongst wet ashes, in moss, at roots 

 of trees : extremely common. I cannot account for this species remain- 

 ing so long undetected in Britain. 



Localities: Ireland — Dublin, very common (Wexford, Cork, and 

 Kerry, E. Percival Wright, Esq.). 



England — Epping Forest, near London, Kent, Chisselhurst, where 

 it seems as common as in Ireland. 



Now first added to British list. 



