278 PROCEEDINGS OF SOCIETIES. 



2. — P. dilatatus {Brandt). 



Synonyms : P. scaler (Auct. and M.-Edw.). 



Body very broad, depressed, rough, and granular; lateral frontal 

 processes very prominent, rounded at apex, and hollowed; median 

 lobe obtusely triangular, moderate ; last ring rounded at apex, plane 

 above. Ischium very flat and broad. Much larger than P. scaler. 



Colour : a uniform slate-gray. 



Habit: crawls very slowly, semi-rolls; extremely brittle in its 

 structure, a touch causing the limbs to fall off. 



Habitat : amongst decaying grass and straw, extremely rare. 



Localities : Ireland — Dublin. Now first added to British lists. 



3. — P.pictus (Auct). 



Synonyms : P. conspersus (?), P. serialis, P. crassicornis (H. Schceffer). 



Body as P. scaler, slightly elongated ; lateral lobes very salient, 

 curved outwards ; median lobe curvilinear, small ; body granulous, last 

 ring triangular, acute at apex, superior surface sulcated. 



Colour similar to P. scaler, but patches more regularly arranged ; 

 may be easily mistaken for Oniscus fossor at first glance, but is more 

 shining. 



Habit : runs with great agility, does not roll. 



Habitat : very local ; dry places, as old ruins, under dry leaves. 



Localities : Ireland — Dublin (local), Belfast (A. H. Halliday, Esq.) 

 England — Chisselhurst, Kent, among chalk-pits ; now first added to 

 British lists* 



4. — P. Icevis (Lam.), 



Body very convex, polished ; lateral frontal lobes slightly salient, 

 small, rounded; median lobe triangular, very short; last ring, apex 

 rounded, deeply sulcate above. The largest of our species. 



Colour : lead-gray, occasionally blotched with yellow on sides. 



Habits: semi-rolls, sluggish. 



Habitat : common everywhere in moist places, especially in stables 

 and litter, among grass at bottom of walls. 



Localities : Ireland — Dublin. England — Kent (one specimen in 

 British Museum Collection, from neighbourhood of London). 



5. — P. pruinosus (Brandt, Conspect. 19.) 



Synonyms: Porcellio frontalis (Lereloullet), preoccupied by Ed- 

 wards. P. macuUcornis (?) (//. Schcejfer). 



Body sub-ovate, oblong, slightly rugged, downy. Lateral lobes 

 small, rounded. Median lobe rounded, minute, almost linear ; last ring 

 triangular, acute at apex ; surface plane. Feet very long. Abdomen 

 much narrower than cephalo-thoracic rings. 



Colour : uniform mouse-colour, marbled under the lens with white. 



Habit : runs with great agility, concealing itself rapidly from the 



