A QUESTION OF PEIOEITY 125 



Cryptosoma, and it is considered to connect Cryptosoma, 

 Brulle, and Platymera, Milns-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 antennge, ' 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-Edwa/rdsii, Miers, was dredged 

 north of the Admiralty Isles from a depth of 150 fathoms. 



Cryptosoma cristatum, Brulle, was depicted in Webb 

 and Berthelot's ' Hist. Nat. des lies Canaries,' and the 

 genus was instituted at page 16 of that work, for which 

 Miers gives the dates 1836-18 14. Milne-Edwards in 1837, 

 while his own pages were passing through the press, refers 

 to BruUe's genus and species as about to be published. 

 In the same year, 1887, de Haan published a new genus 

 and species, Cycloes granulosa, from Japan. lii 1841 he 

 states that Brulle'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 Cycloes, 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 Portunidse. 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 binuv- 

 culatus by Herbst in 1790, and manmdllaris 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.' 



