140 Scientific Intelligence. 
He considers the characters of the external antenne, particularly of their 
ld divi 
second joint sarees of paramount importance, and wou id 
the suborder Brachyura, in accordance with these characters, into four 
groups, nam 
Orbata, with the first two _ of the antenna only present, the rest 
wanting, as in Acanthocyclus. 
Liberata, with the’ sbasicerite free, as in Oncinopus 
Incuneata, with ~ wri wedged i in between the pterygostomium 
and the epistome, as 
Perfusa, with the Wadeaeits completely united with the neighboring 
parts, as in Stenorhynchus. 
These differences are certainly of great importance, and have not 
enerally received sufficient attention from carcinologists. But they 
ean scarcely be used for the primary subdivisions, as they are not coin- 
cident with characters of still higher! value. By their use we should 
pe ceo to dismember well-marked groups ;—to separate for instance, 
rocheira from the Maioids and Gecarcinus from the Ocypodoids j— 
; while strange approximations would occur, as of Oncinopus with Myeti- 
ris. Experience has long since shown us = it is impossible to group 
rated as a distinct group; but they should no more be u 
Parthenopine than should the a which Dr. Strahl sen unite 
with the Leucosidea, although these are far more nearly allied to the 
Calappide, not having the afferent ca covered by the exognath 
the outer maxillipeds, which is the case in all Leucosidea. 
Again, Dr. - remarks, “ The genus etait limited by the rejection 
of Leptograpsus, Metopograpsus, etc., and represented by the species 
Pharaonis, sae Webbi, etc., must be removed not only sp of the 
Grapsoidea, but even entirely out of the Brachyura, because the struc 
ture vot the ‘external antenne differs completely from that which prevails 
amongst the Brachyura. G@rapsus, for instance, has no operculum at the 
base of the external antenz, but a perforated tubercle, as in the ear 
and must therefore at least be placed among the ager Here we 
would have sl of OS variegatus and Grapsus strigosus, for instance,” 
forms so closely allied that they are placed in one and the same genus 
