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the carapace (in S. carolinensis the distance between the posterior teeth is greater than that 

 between the preceding) and by the chelae being granulate, not smooth. 



Notwithstanding the differently-shaped abdomen, the "Siboga" specimen truly belongs 

 to • Speocarcinus, and this is the first instance of a representative of the genus outside the 

 American waters. 



Dimensions in mm. : 



Fronto-orbital breadth 2.75 



Breadth of front 1.55 



Greatest breadth of carapace . . . 3.85 



Length of carapace 2.85 



Length of penultimate pair of legs . 8.5 



Lophoplax n. g. 



The "Siboga" expedition yielded two remarkable Brachyura, which in my opinion, are 

 somehow related to the Goneplacidae, and more particularly to the Prionoplacinae. Dr. J. G. 

 DE M.\N, to whom I sent the larger cf, kindly informed me, that he could not identify it with 

 any known form, and that it should rather belong to a new genus incertae sedis. I propose to 

 bestow the name Lophoplax on it, the diagnostic features of which are as follows : Carapace 

 thickly pubescent, granulate beneath the fur and with the various regions distinct, lateral margins 

 all along with a series of blunt, depressed teeth, front strongly deflexed, bilobed. Chelipeds 

 heavy, meropodite and carpodite pubescent, like the carapace. First segment of abdomen of cf 

 entirely occupying the space between the bases of the posterior legs, second segment much 

 narrower, third segment again produced laterally, but not reaching to the coxopodites of the 

 last legs; last segment of sternum exposed at anterior corners. 



It is this character of the abdomen, which in my opinion refers the new genus to the 

 present subfamily Prio7ioplacinae and more particularly to genera exhibiting a similar feature, 

 such as Euryplax, Eucralopsis, Panoplax, Oediplax and Homoioplax, which, however, are 

 distinguished by having at least one tooth less behind the external orbital angle (in LopJioplax 

 there are five of such teeth, none of which are spiniform);. these genera are, however, with 

 exception of Homoioplax, very obscurely known. 



The genus is founded on ; 



I. Lophoplax bicristata n. sp. PI. 12, Fig. 2. 



Stat. JT. Borneo Bank, Strait of Makassar. Depth 59 m. i cf- 



Stat. 260. 5° 30.55., I32°55'.2E. North west of Kei Islands. Depth 90 m. i cf- 



The carapace of this species is subquadrate, the distance between external orbital angles 

 being very slightly less than the length of the carapace. The surface of the latter is every- 

 where concealed under a thick fur of short, club-shaped hairs, which are somewhat longer on 

 the eye-stalks and especially across the front; it is only when this fur is thoroughly removed 

 (as has been done on the right .side of the figure) that the sculpture of the carapace is to be 



48 



