REPORT ON THE BRACHYURA. 
V 
including the groups Dorippidea, Calappidea, Matutoidea, Leucosidea, and Raninoidea. 
In the first named division (Brachygnatha) the subdivision Cancroidea includes not only 
the Cyclometopa, but also the Catometopa or Grapsoid Crabs, and the Corystoidea 
(Corystiens) of Milne Edwards. 
This system, based in large measure upon the structure of the maxillipecles (upon the 
study and illustration of which in the different types of the Brachyura de Haan bestowed 
so much time and labour) has been adopted by few other authors . 1 
W. S. MacLeay in 1849 2 somewhat fancifully divides the Brachyura into two primary 
sections, the first, Tetragonostoma, including the stirpes Pinnotherina, Grapsina, 
Cancrina, Parthenopina, and Inachina, the second, Trigonostoma, including the stirpes 
Drominia, Dorippina, Corystina, Calappina, and Leucosina. 
The value of the great subdivisions proposed by de Haan, and of his minor groups or 
genera, was discussed at length by Professor J. D. Dana in 1852, in the introduction to 
his elaborate Report on the Crustacea collected during the U.S. Exploring Expedition 
under Captain (Commodore) Wilkes, U.S.N., 3 and the defects of his classification are 
pointed out. It will be unnecessary here to reproduce in detail the system of arrange- 
ment proposed by Dana, who not only characterised anew the families and subfamilies of 
the Brachyura, but gave diagnoses of all of the then known genera ; it will be sufficient to 
note, that the four great groups of the Brachyura proposed by Milne Edwards are retained 
nearly as they were defined by that author, and the Dromiacea and Raninoidea, included by 
de Haan in the Brachyura, are restored to the Anomura. Dana’s classification, as regards 
the subfamilies and minor subdivisions, has been considerably modified by A. Milne Edwards 
in 1861-65 as regards the Cancroidea, 4 and by myself in 1879 5 as regards the Oxyrhyncha. 
He divides the Oxyrhyncha into the legions Maiinea, Parthenopinea, and Oncininea, 
the latter section restricted to the genus Oncinopus, which in my revision of the group is 
placed near Macrocheira in the subfamily Inachinse ; the Cyclometopa or Cancroidea into 
the legions Cancrinea, Thelphusinea, and Cyclinea (the latter restricted to the genus 
Acantliocyclus ) ; for the Catometopa and Oxystomata the division is into families only, 
for which I must refer to his Report ; no primary sections or legions are established in 
these groups. 
His subdivisions in the Oxyrhyncha, Cyclometopa, and Catometopa seem to me some- 
times needlessly numerous, but his primary sections and his arrangement of the leading- 
groups of the Oxystomata are followed in the present Report. 
Professor Dana’s system, offering as it does facilities for the classification and 
1 It was, however, followed by Dr. F. Krauss in his work entitled Die sud-afrikanisehen Crustaceen, Stuttgart, 
4to, 1843. 
2 Annulosa of South Africa in Smith’s Illustr. of Zoology of South Africa, p. 54, 1S49. 
3 Crust, in U.S. Explor. Exped., vol. xiii. (i.) pp. 69-75, 1852. 
4 Archives du Museum, vol. x. pp. 309-421, 1861 ; Nouvelles Archives du Museum, vol. i. pp. 177-303, 1S65. 
6 Journ. Linn. Sec. Lend. (Zool.), vol. xiv. pp. 634-673, pis. xii., xiii., 1879. 
