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426 ) : Scientific Intellurence. á 
side, so that the true apical margin slopes backward and outward. "he 
fourth joint is articulated with the same part normally in both, and the 
only difference is in the greater or less inclination of the summit mar- 
gin, when greatest it approximating to longitudinal. — "The little import- 
ance of the distinction based upon the maxillipeds among the Cancroidea 
as well as Maioidea is shown by numerous instances. Even the single 
genus Xantho presents wide variations, as the joint may be either trans- 
verse or oblong. (Compare Xantho Orbiguii, Edw. with other species.) 
"T hesystem of De Haan for this reason, although developing some new re- 
lations, contains many ambiguities and incongruous associations, not- 
withstanding the learning of its author, the remarkable skill and accu- 
racy of his "work, and the vast additions of facts he has made to the 
science. We have admired the wonderful fidelity of his plates, the 
thorough spirit of investigation displayed through his magnificent volume, 
and the judgment with which he has seized upon typical forms in insti- 
tuting his genera. Yet we can not but object to his defective system of 
arrangement and description, by which his types are often thrown into 
wrong associations, and the groups they typify are laid down with false 
limits,--the characters to be derived, (as the system of Milne Edwards 
illustrates) from organs of real importance in the species, being sacri- 
ficed in a great degree to indications from the maxillae or maxillipeds. 
In the distribution of the Mailoidea, we disregard, for the reasons 
stated, the older subdivisions of Macropodineà and Maiinea, and arrange 
their species into families and subfamilies as below, according to the 
characters of the eyes, antennc and other organs, using these characters, 
in the order, as far as we can judge, of their relative bearing upon the 
functions or habits of the species. 
De Haan has separated on good grounds Latreillia from the other 
genera, having shown that the posterior legs are short, dorsal, and more 
or less prehensile, asin Dromia,and that the vulvae have the same position 
as in that genus (in the base ofthe feet of the third pair) ; and he therefore 
places the genus in the Dromia group. Still, in the number of branchice 
and some other characters, it is like the Maiinea, and it is properly an 
intermediate type... "The outer antennz are peculiar in being free and 
cylindrical from the very base, with the second joint much longer than 
the first, nearly as in the Dromiacea. "These last facts with regard 
to the antenna are also true of another genus having the posterior legs 
prehensile, somewhat Dromia-like, although they are not at all dorsal 
and also resemble the preceding legs. The genus referred to 1s Onci- 
nopus of De Haan. It is apparently intermediate in Pine between 
the Maia tribe and Latreillia. 
The aberrant form, Oncinopus, (and also Latreillia, if it be not thrown 
with the Dromiacea,) will naturally belong to a distinct group, and we 
therefore divide the Maioid Crustacea into three tribes, MArINEA, ONci- 
NINEA and PARTHENOPINEA. 
The Parthenopinea have the basal joint of the outer antenne usaally 
filling a hiatus in the orbit, as in most Cancroidea, and not projecting 
beyond the eyes, besides being more inward and posterior in position, . 
and free or bounded laterally by sutures; while in the Maiinea this joint lies 
directly below the eye, projects beyond it, and is commonly soldered to 
the shell outside of the joint. "The Parthenopinea are thus intermediate 
