BIHANG TILL K. SV. VET.-AKAD. HANDL. BAND 17. AFD. IV. N:o 9. 7 
being flattened or dilated; they perfectly resemble the legs 
of Cryptocellus foedus, according to WEstWoop's figures; and 
the tarsi are all thick and obtuse, whereas in H. L.'s and 
GERVAIS” figures of Cryptostemma Westermanni the six poste- 
rior tarsi are much more slender than the preceding joints. 
These differences are very puzzling. On the one side, 
it does not seem probable that GUÉRIN-MENEVILLE should have 
described the legs of his species as being »aplaties», without 
there being really some reason for calling them so; on the 
other hand it appears very strange that two animals belon- 
ging to this curious Suborder, and living nearly in the same 
parts oftropical Africa, should differ so much in the form of the 
legs, though they would seem to resemble each other perfectly 
in almost all other particulars, as in the number of the jointe 
of the tarsi of the different pairs of legs, in the form of the 
»Lruncus», the hood and the palpi, etc. It is possible (though 
scarcely credible), that the differences in question are sexual, and 
that GUÉRIN-MEÉNEVILLES specimen is a male, and the other a 
female; but I am not aware of analogous differences between 
males and females existing in any other group of Opiliones. 
At all events, the specimen in question well deserves to 
be described in detail, and figured. From Cryptocellus, which 
it perfectly resembles as to the legs, it differs in the form of 
the abdomen and of the cephalothorax: in Cryptocellus foedus, 
in fact, the abdomen is scarcely longer than broad; its ce- 
phalothorax is more strongly narrowed from behind forwards, 
and the hood therefore smaller than in Cryptostemma Wester- 
mann: and in our specimen. For this latter a new genus 
must be founded, if the legs of GUÉRIN-MÉENEVILLES species 
really are, in both sexes, such as he describes them; for the 
present, however, I refer it to Cryptostemma, but think it 
different from the C. Westermanni, the figure and description 
of which show a few deviations (besides those in the form 
of the legs), from what I see in the specimen caught by ArF- 
ZELIUS: in this, f. inst., the impressions on the dorsal seg- 
ments of the abdomen are parallel, not »oblique», and the 
hood is without the »faible sillon longitudinal au miliew>, 
which is said to exist in C. Westermanni. I call our species, 
in memory of its discoverer, Cryptostemma Afzelii. 
I shall now give a description of this species, preceded 
by a tabular view of the Suborders into which I think the 
