ONISCUS ASELLUS. 469 



p. 163. KiNAHAN, Nat. Hist. Rev. vol. iv. 1857, 

 p. 276, pi. xix. figs. 10, 11, 12, pi. XX. fig. 11, pi. xxi. 

 fig. 5a. Bukgersmjk, Amiotat. p. 50. Schnitzler, 

 Onisc. Agri. Bonn. p. 22. 



The upper surface of the animal is glossy and deli- 

 cately punctured, as seen under a lens, the head and 

 segments of the body being dorsally furnished with 

 longitudinal raised spaces, leaving the posterior margin 

 of each smooth. The head is received within a deep 

 emargination of the anterior segment of the body, the 

 anterior angles of which extend even in advance of the 

 two prominent lateral lobes of the head. The inner 

 antennse are minute and three-jointed, the terminal joint 

 being the longest and most slender, with a slight setose 

 notch near the apex. The outer antennse have the basal 

 joint small, the second short, but broad and dilated at its 

 base on the outside ; the fifth joint is the longest, the 

 three terminal joints being much more slender, and not 

 more than two-tliirds of the length of the fifth joint (in 

 our magnified outline figure, c, the articulation between 

 the two terminal joints is much too strongly marked) ; 

 the tip of the eighth or terminal joint is furnished with 

 a minute spine. 



The labrum is membranous, and composed of two divi- 

 sions, each of which is oblong in form, rounded at the 

 extremity, where is a deep narrow notch or fold, the 

 inner angle being somewhat more advanced, rounded off, 

 and finely setose : the right-hand division is represented 

 in figure lb'. 



The mandibles are strong and horny, oblong in form, 

 strongly angulated on the outside, the apex being at 

 right angles with the base, and terminated by a compound 

 tooth, with three or four short curved spatulated bristles 

 along the margin, the inner angle of which is furnished 



