122 "WW Scientific Intelligence. 
are less numerous, as in the Grapsoidea. 'T'he outer antennz are obso- 
lete, and the inner in Corystoides have no fossettes. "They are there- 
fore genera of low grade, at the foot of the Cancroidea, and approach 
closely in rank to the Corystoidea. 
Our grand divisions of the Cancroidea are hence, 
]. CawNcRINEA, or CaNwcROIDEA Tyrica. 
2. 'TTELPHUSINEA or CANCROIDEA GRAPSIDICA. 
9. CvcLiNEA, or CaNcROIDEA CORYSTIDICA. 
The character of the efferent passage or canal, separating the Leu- 
cosoid Crustacea or Oxystomata, is the most striking among the 
Brachyura. While, in all other species, this passage passes over the 
outer portions of the palate or przlabial area, in these, it passes over 
the medial portions, and terminates at the middle of the front margin of 
the buccal area which is therefore elongated, giving the area a triangu- 
late outline: the character of this passage and not the form of the area 
is the important character of the Leucosoidea. "The inner branch of the 
lst pair of maxillipeds is modified to correspond, as it covers (more 
or less perfectly) in this and all the Brachyura the efferent passage. 
The efferent passage, which affords the striking character alluded to, 
has its different degrees of perfection among the Cancroidea. In a 
large number of genera, the waters wash over the palate without any 
confining ridge: but in others there is a distinct ridge, running longi- 
tudinally, near the middle of either lateral half of the palate, and 
terminating at the front margin of the buccal area. This ridge is 
prominent in. Eriphia, Ruppellia, Ozius, Pilumnoides, Melia (as the 
writer has observed) and some other genera, and is also distinct in 
Pilumnus. It is wanting in Cancer, Xantho, and the allied, or if a 
trace is to be observed, (as in Menippe Rumphii and some other spe- 
cies,) it does not reach to the front margin of the buccal area. We 
have in this character, therefore, an important distinction separating 
the non-natatory Cancrinea into two groups, the Cancride and the 
Eriphide. Mere breadth of carapax alone is of very little value as a 
characteristic: Xantho passes by its allied genera into species but 
little broader than long, and so with Chlorodius. 
Among the swimming species, a large part, as detected by De Haan, 
have a small lobe attached to the inner margin of the inner branch of 
the 1st maxillipeds: while others, as Platyonychus and the allied have 
no such lobe and approximate somewhat to the Corystoidea, although 
not properly, as we think, of that group. 
The species of Lupa and Thalamita bave a ridge upon the palate 
either side bounding the efferent passage ; but there is one exception 
in Lupa cribraria, which species consequently must pertain to a dis- 
tinct group from the other Lupas. 
In these brief remarks on the classification of the Cancroidea, we 
leave much to be gathered from the following synopsis. But a few 
words should be offered on the genera of De Haan and Edwards; 
partly because the two are to some extent in conflict, and partly be- 
cause several of those of De Haan are of unesscrtiBl importance. 
'The publication of the first foscicle of De Haan's Crustacea of the 
Fauna Japonica in 1833, preceded Edwards by a year, but the descrip- 
tions of his genera were so concise and imperfect that it was not possi- 
ble for any one to have recognized them all. 
