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. Subbrauchial 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, 32 mm. 



Station 3427. 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 

 m Ui'patus or in Omcliila tuherosa Stimps. [0. acuia Stimps. and 0. stimpsomi 

 Studer I have not seen). The third, fourth, and fifth abdominal segments 

 in the male are fused into one, as in Hcpatus and 0. tuherosa. 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 Adceomoryha Miers, a genus which must be closely 

 allied to Osachila. The second and third segments of the antennre are present 

 in Osachila, but only as the merest rudiments. 



Three species of Osachila have been previously described : 0. tuherosa 

 Stimps.* from the Antilles and o£E Cape Hatteras, 36-164 fathoms ; 0. acuta 



* Bull. Mus. Comp. Zool., IT. 154, 1870. 



