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by narrow sinuses and not prominent, that the supra-orbital margin has two notches and that 

 the chelae are provided with longitudinal rows of granules, whereas in S. carolinensis^ from 

 West-India, and 5. ostrearicola^ from Peru, the antero-lateral teeth are more prominent (five in 

 the former, the anterior one being fused with the external orbital angle, and three broad, flattened 

 ones in the latter species), the supra-orbital margins are not notched, at least according to 

 figures, and the chelae are quite smooth. 



All four species are American ; the type species (5. carolitieiisis) is known to inhabit 

 subterranean galleries, excavated in the mud of shallow water, j^robably by other animals. It 

 is this habit that gave rise to the generic name. 



Among the Brachyura of the "Siboga" I found one animal, which, on account of its 

 striking resemblance to the type species, is considered to be a new species of Speocarcinus. 



I. Speocarcinus celebensis n. sp. PI. ii, Fig. i. 



Stat. Ii6. West of Kwandang Bay entrance, north coast of Celebes. Depth 72 ni. i cf. 



This small specimen exhibits most of the distinctive characters of the genus and conse- 

 quently I have referred it to Speocarcinus, though the third segment of the abdomen is scarcely 

 produced laterally and the fourth to sixth segments are not coalesced. 



The ratio of the length of the carapace to its greatest width is i : 1.4^), its surface is 

 much convex in longitudinal direction, but nearly straight transversely. Regions are fairly well 

 to be made out : the mesogastric area is distinctly outlined, the protogastric lobes are defined 

 anteriorly by two epigastric ridges, between which a deep furrow divides the surface of the 

 front: a sulcus separates the hepatic region from the protogastric and branchial areas, which 

 themselves shade into one another; a cardiac area is also seen behind the cervical groove. The 

 surface of the carapace is somewhat granulate towards the margins, which are fringed with 

 hairs ; these hairs are also seen on the subhepatic and subbranchial regions. 



The front is vertically deflexed, its width is more than one-half (exactly 56°/^) of the 

 distance between the external orbital angles, or rather of the fronto-orbital breadth ; in dorsal, 

 and also in ventral view, it is inflated, made up of two equal, rounded lobes, separated by a 

 deep furrow, but in anterior view the free margin is regularly convex ; the lateral angles are 

 not produced. The orbits are small, marginal, the supra-orbital margin forming scarcely a distinct 

 excavation in the regular outline of the carapace, which excavation is completely fiUed by the 

 short eye-stalks, terminating in a very small eye, chiefly situated ventrally. The supra-orbital 

 margin is entire, not notched, transverse, passing with a gentle curve into the lateral margin 

 of the carapace, so that an external orbital angle is. not formed. The antero-lateral margin of 

 each side, however, presents three epibranchial teeth, the first of which is the larger, 

 well defined by deep sinuses both anteriorly and posteriorly, somewhat flattened, but ending in 

 a short spine, directed forward ; the second and third teeth, at the level of which the carapace 



l) In S. carolinensis, to which this species shows the greatest affinity, the ratio is I : I.3 in Porto Rican specimens and in one 

 from' Tortugas ; in a specimen from Charleston (South Carolina) the ratio is less and intermediate between the Porto Rican specimens and 

 the type specimen, which latter presents tlie narrowest carapace (Rathkun Buil. l'. S. Fish Comm. for 1900, v. 2, 1901, p. 11). 



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