XII ANATOMY eye 
which extend backwards, each having five lobes. There are also 
two median diverticula which proceed from the ventral surface 
and pass through the endosternite. The abdominal portion of 
the canal is entirely concealed by the great “liver” mass which 
communicates with it by four paired ducts in the anterior part 
of the abdomen. Behind the fourth abdominal segment the gut 
is narrow till it expands in the seventh segment into an hour- 
glass-shaped stercoral pocket which, according to Laurie, is a 
portion of the mesenteron. 
The excretory organs are the Malpighian tubes and the coxal 
glands. The former are generally described as entering the 
anterior portion of the stercoral pocket, but according to Laurie 
they pass along its ventral surface, attached to it by connective 
tissue, and really enter at the posterior end. The coxal glands 
are well developed, and lie beneath the endosternite, opening 
near the first coxae. 
The nervous system is much concentrated and of the usual 
Arachnid type. The median abdominal nerve has a ganglion 
towards its extremity, supplying, according to Bernard,’ the 
muscles which move the tail. The heart is extremely long, and 
varies little in width. It has nine pairs of ostia two in the 
thorax and seven in the abdomen. The generative glands are 
paired, and in the male there are large seminal vesicles. In the 
most ventral portion of the abdominal cavity hes a remarkable 
asymmetrically-situated gland, the “stink-gland.” It consists of 
a number of secretory tubules communicating with two elongated 
sacs, one of which lies beneath the nerve-cord, and therefore 
medially, while the other lies far to the left. Their ducts 
proceed to the anus or its vicinity. 
The caudal organs, or white spots which, as already mentioned, 
are usually found on the last of the three post-abdominal seg- 
ments of ZVhelyphonus, are of doubtful function. They have 
been variously explained as the stink-gland orifices, and as organs 
sensitive to light (“ommatoids”). Laurie® was unable to find 
any pore in this region, nor was there any of the pigment so 
characteristic of organs of sight. The histological structure 
indicated a sense-organ rather than a gland, but the use of these 
organs is entirely conjectural. 
1 Tr. Linn. Soc. (2) vi., 1896, p. 344. 2 Bernard, Joc. cit. p. 366. 
3 J. Linn. Soc. xxv., 1894, p. 29. 
