ONISCUS ASELLUS. 469 
p. 163. Krnanan, Nat. Hist. Rev. vol. iv. 1857, 
p. 276, pl. xix. figs. 10, 11, 12, pl. xx. fig, 11, pl. xxi. 
fig. 54. Burerrspisk, Annotat. p. 50. Sonnrrzuer, 
Onisc. Agri. Bonn. p. 22. 
Tue 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 
antennee are minute and three-jointed, the terminal joint 
being the longest and most slender, with a slight setose 
notch near the apex. The outer antenne 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-thirds 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 /b’. 
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 
