8 THORELL, A NEW ARACHNID. 
Opiliones should at present be divided, and a characteristic 
of the Suborder RKicinulei and the Family Cryptostemmoide, 
as also of the genus Cryptostemma, under the supposition 
that our C. Afzelii really belongs to that genus. Cryptocellus, 
WEsTW., differs, as I have already stated, from Cryptostemma, 
GuÉR., nob., perhaps only by the shorter abdomen and the 
cephalothorax more tapering forwards. If Gibbocellum, STECK., 
really is an Opilio, a separate Order must probably be created 
for its reception. ' 
The characters that have hitherto been considered as 
common to all Opiliones, must, after the discovery of Crypto- 
stemma and Cryptocellus, be much reduced in number; and 
these characters are, as may be seen from the following 
attempt at a definition of the Order, mostly negative. From 
the Chelonethi the Opiliones are, if we leave aside Gibbocel- 
lum, easily distinguished by the palpi not ending in well de- 
veloped pincers, by the want of spinning-organs opening on 
the mandibles. and by the spiracles being only two, not four. 
From the Acari the Opiliones are scarcely in all cases di- 
stinguishable by any other external character than the struc- 
ture of the abdomen, which, in the Opiliones, is evidently 
segmented at least at its posterior end. 
Ordo Opiliones, Sunp., 1833. 
Abdomen tota latitudine sua cum cephalothorace con- 
juncetum, saltem postice distincte segmentatum, cauda vel pro- 
cursu caudali carens. Mandibule didactyles, organis nendi 
carentes. Palpi aut apice inermes, aut ibi unguiculo vel ungui 
singulo prediti, non in forcipem perfectam exeuntes. Omnes 
pedes unguiculati. Spiracula duo, ad basin ventris sita, in 
! Since I had the good luck to receive, for examination, an animal 
belonging to the Ricinulei, I am no longer so fully convinced that Gibbo- 
cellum belongs to the Chelonethi, and not to the Opiliones, as I formerly 
was. The most important characteristic, that seems to unite Gibbocellum 
with the Chelonethi, viz., the maxill& being of the same form and direction 
as the coxe, which are all destitute of a maxillary lobe, belongs also to 
the Ricinulei; as to the other marks, on the strength of which I referred 
that genus to the Chelonethi, f. inst. the presence of spinning organs, 
the four spiracles, as also the expressions used by Strecker regarding the 
mouth parts and the anatomy of his G. Sudeticum, it is quite possible 
that that author's statements are erroneous: conf. SÖRENSEN, loc. cit. Be- 
fore we get a trustworthy description of that highly interesting animal, it 
is impossible to decide with certainty as to its true systematic afinities. 
