210 
Dr. Kidd on the 
other ; and it is in consequence of the looseness of these mem- 
branes that the animal is enabled either to separate the con- 
nected parts to a considerable distance from each other ; or 
to contract them so closely together as to hide the interposed 
membranes from view ; and, from the arched form of the 
anterior part of the thorax it can draw in its head under that 
part, much after the manner of a tortoise. The same flexi- 
bility of the connecting membranes enables the animal to 
place either its head or its thorax at a considerable angle with 
the rest of the body ; a movement which is very charac- 
teristic of this insect, and Ogives it an air of intelligence; the 
attitude being apparently that of watching, or listening. 
The head* All the upper part and the sides of the head 
form a hard, thick, horny case, containing the various mus- 
cles which move the jaws ; and, in order to strengthen this 
case, two firm bars run transversely across the bottom both 
of the anterior and posterior margin ; which bars are them- 
selvesunited together by a still stronger bar or beam, which 
runs longitudinally from the middle of the one to the middle 
of the other. There is nothing very remarkable in the parts 
which constitute the mouth, excepting the maxillary and 
labial palpi. In the maxillary palpi there are five joints or 
parts ; in the labial there are three ; and the last of these 
joints in each of the palpi terminates in a rounded extremity, 
like a pestle ; this extremity, which is of a honey-yellow 
colour, is perfectly smooth, while, every other part of the 
palpi has a rough and hairy surface. In their natural posi- 
tion the palpi are bent and projected forward, so as to re- 
‘ semble the fore-legs of a horse in the act of cantering. 
• Vide Fig. i and z, Plate XV., 
