. Carnegie Institution of Washington publication. 50 Papers from the Department of Marine Biology. That which is significant is not that the endopodite has become slender, but that the appendages have been forced so far apart. The second and first maxillipeds are fairly typical and call for no par- ticular remark beyond the description of Caiman. The second maxilla consists firstly of a small triangular plate, the base of which is free and directed inwards, which represents the proto- podite, not divided into a basipodite and coxopodite as in Cancer (where each again is bilobed). The inner bor
. Carnegie Institution of Washington publication. 50 Papers from the Department of Marine Biology. That which is significant is not that the endopodite has become slender, but that the appendages have been forced so far apart. The second and first maxillipeds are fairly typical and call for no par- ticular remark beyond the description of Caiman. The second maxilla consists firstly of a small triangular plate, the base of which is free and directed inwards, which represents the proto- podite, not divided into a basipodite and coxopodite as in Cancer (where each again is bilobed). The inner border is provided with many setae. Internally the appendage passes into a narrow neck, where a second bunch of setae is given off and where a possible articu- lation occurs. Secondly, there is an exopodite, the scaphognathite, which attains the development usual in the Brachyura. The con- nection between the protopodite and the exopodite is very slender, thus differing from that in Cancer and other crabs. The protopodite sub- serves nutrition and its rudimentary character is thus strongly con- trasted with the normal devel- opment of the exopodite, which performs a respiratory func- tion. The partial disconnec- tion of these two parts which appears to be in progress is perhaps due to the fact that their rhythmical movements do not coincide. The endopo- dite, found in other Brachyura, is wanting here. The first maxilla shows a much greater reduction, since it is entirely masticatoiy in function. It is represented by a slightly curved, slender plate representing the protopodite. It is less than a quarter of the size of that of the second maxilla. It is undivided in contrast to the bilobed protopodite of other Brachyura. A few setae are present internally. The endopodite is absent. The mandibles are two smooth triangular plates, thin but more strongly chitinised than the other buccal appendages, with straight internal edges, not broad or much thickened, so as to serve for mastica- t
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