280 PROCEEDINGS OF SOCIETIES. 



sub-glabrous. Terminal ring of abdomen : posterior border regularly 

 arcuated in the middle. Coxae as acute angles. Abdominal false feet : 

 peduncle oblong, slightly shorter than last abdominal ring. Ischium 

 and accessory appendage twice the length of peduncle. 



Colour : yellowish-brown, the young prettily diced with white. 



Habits : runs with agility, or rolls up extremities of body, and feigns 

 death ; very common among vegetable debris, along tide- marks, and on 

 rocks ; seldom takes water ; may be seen running over sand in full sun- 

 shine. 



Common around Ireland. 



Family.— PHILOSCIADA 



Genus. — Philoscia (Zatreille). 



1. — Philoscia muscorum (Zatreille). Plate XX., Fig. 1. 



Synonyms : Ligia melanocephala (H. Schceffer), Oniscus sylvestris (?) 

 (Fabric), Oniscus muscorum (?) (Cuv.). I have not been able to 

 verify the reference queried. Philoscia muscorum (Zaddach, Syn. Crust. 

 Prussic, p. 14). 



Body flattened, elliptical, perfectly smooth and glistening. Head 

 transversely elliptical, arched in front ; neither lateral nor median lobes. 

 Internal antennae three-jointed. External antennae: second joint of 

 peduncle not swollen at base. Tige three-jointed; articulations rounded, 

 tumid, the last terminating in a hair, a long spine at apex of fourth 

 and fifth articulations, all the articulations both of peduncle and tige 

 densely hairy. Coxae of abdominal rings somewhat linear; abdomen 

 abruptly narrower than seventh cephalothoracic ring. Last ring 

 broadly triangular ; apex acute. Abdominal false feet, last pair, attached 

 to exterior margin of ultimate ring, uncovered. Peduncle somewhat 

 quadrilateral. Ischium trigonal, spinous along edges, fine hairs be- 

 tween spines, with a slender filament at its apex. Accessory appendage 

 not quite half length of ischium rounded, hairy. Accessory lobe tri- 

 angular, distinct, nearly attaining apex of ped ancle. 



Colour fulvous, with dark black patches, a dark stripe generally 

 along median line. A pale salmon-coloured variety was brought me by 

 E. Percival Wright, Esq., from Wexford, which I have found since rather 

 common on Bray Head, county of Wicklow, and occasionally about 

 Donnybrook, county of Dublin. 



Habitat : dry places among leaves, also among sand hills, along sea- 

 shore, under stones ; common near sea. 



Habits : runs rapidly, feigns death, but does not roll into a ball. 



Localities : Ireland — Dublin, extremely common ; Wicklow, Meath, 

 (Wexford and Cork, E. Percival Wright, Esq.), Belfast (A.H. Haliday, 

 Esq.) England — Middlesex, Essex, Kent, common. 



A species which has been much misunderstood, although an cx- 

 tromely common species. 



