476 ONISCID^E. 



Arzn. Thiere, ii. tab. 12, f. 1, 2, 3, 4. JOHNSSON, 



Syn. Framst. Sver. Onisc. p. 21. ZADDACH, Syn. 



Crust. Pruss. p. 12. BURGERSDIJK, Annot. p. 39. 



SCHNITZLER, Onisc. Bonn. p. 23. 



Oniscus granulatus. LAMARCK, Hist. Anim. sans Vertebr. v. p. 261. 

 Porcellio dilatatus. BRANDT and RATZEB., Arzn. Thiere, t. 12, f. 6. 



BRANDT, Bull. Moscow, vi. p. 176. 



Oniscus asellus. FABRICTUS, Ent. Syst. Suppl. p. 300. 



Porcellio Brandtii. MILNE EDWARDS, Crust, iii. 168 (var.). 

 Porcellio dubius. KOCH, in Cont. Panz. Heft. 180, n. 8. 



Porcellio affinis. KOCH, in Cont. Panz. Heft. ISO, n. 13 (var.). 



THIS species is at once distinguished by the entire 

 upper surface of the animal being strongly marked with 

 round and elevated tubercles. The lateral lobes of the 

 head are very prominent, and rounded at the outer 

 angles, whilst the central lobe is strongly produced and 

 nearly triangular. The animal is more or less ovate in 

 form, and moderately convex, with the posterior angles 

 of the segments of the body moderately produced and 

 pointed. The outer antennas have the second joint 

 dilated internally at its base. The fifth joint is the 

 longest, and the two terminal joints united are about 

 two-thirds of the length of the fifth. The upper lip is 

 formed of two flattened membranous plates, of each of 

 which the outer apical angle is rounded, and the inner 

 angle slightly extended, dilated, and setose. The right- 

 hand division of this lip is represented in figure W '. The 

 mandibles are horny, strongly angulated on the outside, 

 the extremity being at right angles with the base, and 

 armed with three teeth, which seen laterally are obliquely 

 truncated. Below this, the inner margin of the mandible 

 beyond the middle is armed with a complicated series of 

 short horny teeth and bristles, the innermost of which is 

 elongated and curved. The inner maxillae are delicate, 

 and armed at the tip with two setose bristles ; the outer 

 maxillae are large, oblong, setose on the outer edge, and 



