A QUESTION OF PRIORITY 125 
Cryptoséma, and it is considered 1o connect Cryptosoma, 
Brullé, and Platyméra, Milne-Edwards, with Calappa 
through such forms as the above- mentioned Calappa 
gallus (Herbst), but Paracyclois is distinguished from the 
first two of these genera by the absence of any lateral 
spine on the margin of the carapace, and the broader basal 
joint of the second antenne, ‘and from Calappa by the 
absence of the clypeiform prolongations of the carapace, 
which are represented by a slight protuberance of the 
postero-lateral margins in Paracyclois, which protuberance 
bears several strong spines.’ The type species of this curious 
genus, Paracyclois Milne-Edwardsi, Miers, was dredged 
north of the Admiralty Isles from a depth of 150 fathoms. 
Cryptosoma cristatum, Brullé, was depicted in Webb 
and Berthelot’s ‘ Hist. Nat. des Iles Canaries,’ and the 
genus was instituted at page 16 of that work, for which 
Miers gives the dates 1836-1844. Milne- Edwardsin 1837, 
while his own pages were passing through the press, refers 
to Brullés genus and species as about to be published. 
In the same year, 1837, de Haan published a new genus 
and species, Cycloés granulosa, from Japan. In 1841 he 
states that Brullé’s species is clearly the same as this, 
and in 1849 he repeats the remark as an example of wide 
distribution, the very same crab being found at the 
Canaries and in the waters of Japan. But he retains the 
name Cycloés, being evidently, and perhaps rightly, under 
the impression that it had priority over Cryptosoma. 
Orithyia, Fabricius, 1798, is strongly distinguished 
from the other genera of this family by the natatorial 
character of the last three pairs of legs, which have an 
ovate terminal joint, as in the Portunide. The three 
preceding pairs of legs have also the terminal joints flat- 
tened, and the others more or less compressed, as is usual 
in species apt for swimming. There appears to be only 
one species, found in the Chinese Sea, and called bima- 
culatus by Herbst in 1790, and mammuillaris by Fabricius 
in 1793. Herbst, whose specific name must prevail, says 
that ‘ without dispute this crab is one of the most beautiful 
and most rare.’ 
