366 ARCTURIDA. 
Tus species is more robust than either of the two 
following; it is also more strongly tuberculated, the 
tubercles extending over the two segments preceding the 
long one, which is somewhat transversely furrowed. 
The head and terminal segments of the body are rather 
broader in the male, but of an equal breadth throughout 
in the opposite sex; the females are twice the size of 
their partners, and of a whitish colour; the terminal 
portions of the body are generally directed upwards. 
The head is almost square, with the eyes prominent and 
nearly circular: the anterior angles of the head are 
produced in front of the eyes, forming a deep frontal 
emargination, in which the anterior (upper) antennz are 
inserted; these are not longer than the head, and have the 
basal joint large, the next row short, and the flagellum 
long, cylindric, and terminated by setz. The lower 
antenne are nearly as long as the body, and very robust; 
the first joint is very short, the second rather longer, with 
a deep external notch, the third about as long as the 
head ; the two next are very long, each being about one- 
fourth of the whole length of the body; the flagellum 
is very short and finely serrated beneath, each being 
gradually smaller, the last terminated by a minute acute 
point; the antenne are usually carried in a downward 
direction, The parts of the mouth are very minute and 
delicate. The lip is transverse, rounded at the sides and 
emarginate in front. The mandibles are small, horny, 
broad, and armed with several teeth, without any palpi- 
form appendage. ‘The interior pair of maxillz are very 
thin, transparent, and deeply ciliated. The second pair 
of these organs are larger, with a terminal lobe anda large 
external sub-articulated appendage, the last division of 
which is much larger than the rest, curved and ciliated 
at the tip. 
