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reaches its greatest width, are spiniform, the former larger than the latter, both directed forward. 

 Behind the teeth the margins of the carapace remain parallel and the posterior one is very 

 long and convex. 



Antennulae short, folded transversely in their fossae beneath the front. Antennae free in 

 the inner orbital gap, reaching laterally to the tip of the first antero-lateral tooth. Epistome 

 short, but distinct, its distal border wavy. Lateral margins of buccal cavity convergent backward, 

 as also the longitudinal axes of the external maxillipeds, which consequently leave a wide 

 triangular space between them ; ischium (fig. ia) slightly longer than broad, and longer than 

 the meriis, which is broader than long, owing to the antero-external angle being conspicuously 

 produced ontward; exognath about half as broad as ischium. 



Chelipeds (the right only is present in my specimen) much shorter than the legs, granulate 

 at outer and upper surface, and hairy, especially on the chela. Meropodite short, inner and 

 outer border somewhat serrate, upper border with a subterminal tooth ; wrist with a flattened, 

 not much prominent tooth at inner angle, which is directed forward; chela (fig. ló) small, palm 

 as long as high and as long as the fingers, borders, especially the upper one, with a row of 

 hairs, which extend on to the fingers, outer surface granulate, the granules being arranged in 

 four groups, stretching longitudinally, the upper and under group of which likewise are continued 

 on the back of the fingers, fingers somewhat compressed, not gaping, irregularly-crenulate at 

 opposite margins, sharply acuminate at the curved tip. 



Ambulatory legs long and slender, the penultimate pair being three times as long as 

 the carapace, the four last joints fringed with rather distant hairs, more closely set on the 

 dactyli. Meropodites six times as long as broad, unarmed, carpo- and propodites elongate, 

 dactyli as long as, or slightly shorter than, propodites, faintly curved near the tip-, in the last 

 pair of legs the propodites are shortened and the dactyli are almost straight and somewhat 

 more flattened than in the preceding pairs. 



The first segment of the abdomen of the cf (fig. ic) is partly hidden under the carapace 

 and occupies three-fourths of the space between the last pair of legs, the second segment is 

 only half as broad as the preceding, and the third about as broad as the second and scarcely 

 produced laterally, the remaining segments are all distinct, not coalesced, 

 gradually decreasing in breadth. This shape of the abdomen differs widely from those of other 

 species (at least 5". carolinensis and 5. gramilimanus) in the third segment being not or scarcely 

 produced laterally and in the third to fifth segment not being fused ; it is, on the contrary, 

 much more Rhizopine-ïik.&. As has been already stated, however, the whole aspect of the 

 "Siboga" specimen so strongly suggests a close affinity to 5. carolinensis, in the sculpture and 

 dentation of the carapace, that a removal of my specimen from the present genus does not 

 appear to be justified. From S. carolinensis the new species is distinguished by the carapace being 

 comparatively broader ^), by the front measuring more than half the fronto-orbital breadth, by 

 the absence of a distinct outer orbital angle, by a less curved course of the lateral margins of 



l) In compaiing Miss Ratheun's figure (Buil. U.S. Fish Comm. for 1900, v. 2, 1901, p. II, textfig. 2) with my own the reverse 

 seems to be the case, but there are individual variations in the West Indian species in the ratio of length and greatest width of carapace. 



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