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THE VOYAGE OF H.M.S. CHALLENGER. 
carinated, with the fourth to the sixth joints sometimes armed with spinules ; dactyli 
slender, styliform and nearly straight. 
The species of this genus are always of small size, and occur very commonly both in 
the Atlantic and Indo-Pacific regions in shallow, or more rarely in deeper water. The 
described forms are very numerous ; but it is probable that were a revision of the types 
and of sufficient series possible, it would necessitate the reunion of many of these recently 
described with the types of the earlier authors. As Professor A. Milne-Edwards, the 
highest authority on the Brachyura, justly remarks, “ It has not yet been proved that 
the number of spines which cover the carapace and limbs may not vary in different 
examples of the same species.” 1 
In the arrangement of the species which follows, I have found it necessary, in the 
present state of our knowledge, to arrange them roughly in geographical and chrono- 
logical order, without regard to their affinities. I must regard the subgeneric 
distinctions recently proposed by Dr. Kossmann (tom. cit. supra, p. 38) and which are 
cited, but apparently not adopted, by Milne-Edwards, as of doubtful value, and there 
are not a few species, which, from the descriptions at present published, could not be 
classed with certainty in any one of the three subgenera he has established. 
European and East Atlantic Species. 
Pilumnus hirtellus, (Linne) = Cancer ferrugineus, Herbst (?). European Seas (to 
35 fathoms, Heller). 
Pilumnus spinifer, Milne Edwards. Mediterranean; Black Sea; Azores, 50 to 
90 fathoms (?). 
Pilumnus villosus, Itisso — Pilumnus spinulosus, Kepler (fide Heller). Mediter- 
ranean ; Black Sea. 
Pilumnus cijfinis, Capello. Setubal, Portugal. (Very near Pilumnus hirtellus .) 
Pilumnus teixeirianus, Capello. Setubal. 
Pilumnus tridentatus, Maitland. Holland ; Black Sea. Perhaps not a true 
Pilumnus; it resembles Pilumnoplax and Heteroplax in the form of the 
marginal teeth (Coll. Brit. Mus.). 
Pilumnus calculosus, Dana. Madeira (?) 
Pilumnus africanus, A. Milne Edwards. Gorea and Angola, St. Vincent, Cape 
Verde Islands. 
South African Species. 
Pilumnus verrucosipes, Stimpson. South Africa ; Simon’s Bay (11 fathoms) ; 
Senegambia, 9 to 15 fathoms. 
1 Crust, in Miss. Sci. au Mexique, pt. 5, p. 280, 1880. 
