52 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
prominence of the inner edge bears in addition a submarginal series of 
six to eight Jong sete; the flagellum is about half as long as the basal 
part, distinctly articulated near the middle, and the terminal fourth of 
the whole length very obscurely multiarticulate and furnished with long 
sete. 
The external maxillipeds, when extended, reach a little by the tip of 
the rostrum; the ischium is nearly twice as long as broad and triquetral, 
with the dorso-internal angle sharply and regularly dentate; the merus 
is slightly shorter than the ischium, nearly as broad as long, expanded 
distally and armed with two obtuse teeth on the inner side and with a 
single tooth outside the articulation of the carpus; the three distal seg- 
ments are slender and together about equal in length to the ischium 
and merus, the propodus being about as long as the merus, and the 
earpus and dactylus successively a little shorter. The epipod and ex- 
opod are well developed, and the basal part of latter reaches considera- 
bly by the merus. 
The chelipeds are equal and about three times as long as the carapax, 
the merus being about as long as the earapax, and the chela considera- 
bly longer. In the females and young males the chelipeds are very 
slender and subcylindrical throughout, with the chela scarcely, if at 
all, stouter than the carpus, and with the digits straight and very 
slender. In the large males the chelipeds are very much stouter; the 
body of the chela is expanded and vertically flattened distally, and the 
digits gape widely at the base, the proximal half of the propodal digit 
being strongly curved and unarmed, while the distal part of the pre- 
hensile edge is straight and minutely serrate like the corresponding 
part of the dactylus, with which it is in contact when the digits are 
closed; the basal part of the dactylus is only slightly curved, but is 
armed with an obtuse tubercle on the prehensile edge near the base; 
and the whole prehensile edges of both digits are more or less hairy. 
The three pairs of ambulatory legs are slender and subequal in 
length, about as long as the body, and the dactyli are slender, strongly 
curved, more than half as long as the propodi, and unarmed. The pos- 
terior legs are very small and slender and of essentially the same form 
as in Munida. There are no epipods at the bases of any of the thoracic 
legs. 
The abdomen is considerably shorter and much narrower than the 
carapax, and its dorsal surface is nearly smooth and devoid of carine, 
except on the edges of the sixth somite, as described beyond, though 
there is a slight transverse suleus on the middle portion of the second 
somite, which is also raised sharply above the small facet which slides 
under the carapax. The epimera of the second somite are broad; the 
third and fourth somites are short, and their epimera very narrow and 
acute; the fifth somite is a little longer than the fourth, and its epimera 
broader and more obtuse than those of the fourth; while the sixth 
somite is slightly longer than the fifth, and the postero-lateral margins 
