GAY 69 
light dirty brown. In young specimens two light-coloured 
patches occur on the median line of the dorsal side. The 
colouration has generally a mottled appearance, the dark 
portions being due to presence of closely packed chro- 
matophores. In injected specimens a close connection is 
observed between the terminations of the fine capillaries 
and the chromatophores. In moulting, the cuticle of the 
posterior half of the body is shed first, and a short time 
elapses before the anterior half is shed, so that individuals 
are often found with the posterior half of the body lighter 
in colour than the anterior half. 
Their food consists chiefly of decaying animal and 
vegetable substances, and from a study of the contents of 
their guts, the latter appear to form a large proportion of 
their diet. In captivity they prefer the weaker members 
of their own species, but there is not much evidence that 
this is a natural habit. 
They are able to run with great rapidity, coming out 
from their dark retreats after sunset to feed, at which 
time they may be caught with the aid of a lantern. The 
best instrument for capturing them during the day is a 
fairly long wire, having the last half-inch bent at right 
angles; by means of this they can be extracted from their 
narrow crevices. 
EXTERNAL CHARACTERS. 
The body is oval in shape, broadest across the fourth 
thoracic segment, and gradually decreasing in size towards 
the posterior end. It is almost twice as long as it is 
broad. The males are larger than the females, the reverse 
being usually the case in Arthropods. They may attain 
a length of 32-34 mm., the width of the thorax reaching 
18 mm. The females are more regularly oval in shape 
