OSACHILA LATA. 33 
branchial; the surface of all of these protuberances is tuberculate, the 
tubercles coarsely punctate, the surface between the protuberances smooth 
and coarsely punctate. Front prominent, bilobed, the lobes separated by a 
completely closed fissure ; frontal margin thick, rounded, with two punc- 
tate tubercles ; antero-lateral margin of carapace sharp; behind the point 
where the subhepatic ridge joins this margin it is divided into five obtuse 
lobes, each of which is denticulate ; postero-lateral margin single, tubercu- 
lated; posterior margin narrow, concave ; two transverse rows of low tuber- 
cles on the hinder part of the carapace anterior to the hind margin. Beneath, 
the subhepatic region and the surface of the outer maxillipeds, sternum and 
abdomen are tuberculated and heavily pitted, presenting an eroded appear- 
ance. Subbranchial area smooth. The merus of the chelipeds is tuberculate 
along the upper edge and outside of it ; carpus tuberculate externally, distal 
and superior margin produced to a cristiform tooth which continues back 
upon the carpus the crest of the superior border of the propodus; propodus 
tuberculate on outer face, the tubercles largest above, superior border forming 
a slight denticulate crest which is split into three indistinct lobes; lower margin 
of hand ornamented with a row of low, but rather large tubercles. The edges 
of the ambulatory limbs are slightly cristate; dactyli pubescent on distal 
portion. There are traces of transverse red bands on the ambulatory legs. 
Length, 24.5 mm., breadth, 52 mm. 
Station 5427. 80 fathoms. 1 male. 
In this species there is a crescentic depression on the margin of the 
pterygostomian region in front of the base of the chelipeds, leading into 
the branchial chamber; this depression is much more strongly marked than 
in Hepatus or in Osachila tuberosa Stimps. (O. acuta Stimps. and O. stimpsonit 
Studer I have not seen). The third, fourth, and fifth abdominal segments 
in the male are fused into one, as in Hepatus and O. tuberosa. In the genus 
Osachila the apex of the merus of the outer maxillipeds is notched or con- 
cave, leaving an opening into the excurrent branchial canal when the outer 
maxillipeds are closely applied to the buccal area. This orifice does not 
exist in Hepatus or in Acteomorpha Miers, a genus which must be closely 
allied to Osachila. The second and third segments of the antenn are present 
in Osachila, but only as the merest rudiments. 
Three species of Osachila have been previously described: O. tuberosa 
Stimps.* from the Antilles and off Cape Hatteras, 36-164 fathoms; O. acuta 
* Bull. Mus. Comp. Zodl., I. 154, 1870. 
a 
