REPORT ON THE ANOMURA. Ill 



of the carpus bears three indistinct teeth, and two or three spiniiles are present on the 

 outer margin ; the propodus Ijears a median rounded carina on the upper surface, and on 

 the smaller chelipede a row of minute spinules on the outer margin (not represented in 

 the figure). Five segments are distinctly visible in the antennal peduncle, and of these 

 the first, third, and fourth are spinose. 



Porcellana rohertsoni, n. sp. (PI. XI. fig. 6). 



Characters. — The carapace is ovate, and smooth though minutely punctate, numerous 

 transverse lines occur on the posterior branchial areas, and a few hairs are present on the 

 gastric region. The front is broad and tridentatc, with the apices of the three projec- 

 tions subacute, the median tooth is considerably broader and more prominent than the 

 two lateral teeth, slightly deflexed, and with a shallow median groove on the upper 

 surface. The antero-lateral tooth placed immediately external to the orbit is subacute. 

 The lateral border is convex and unarmed, witli the exception of a rounded projection 

 behind the point where the ill-defined cervical groove passes on to the carapace ; 

 the anterior portion of this border is sharply defined, the posterior third is simply 

 rounded. The posterior border has a double outline and is almost straight. The eyes 

 are of small size, with the corner deeply pigmented. The first joint of the antennal 

 peduncle is prominent and acute, forming a fiattened process below the orbit ; the 

 flagellum is of moderate length. The pterygostomial area bears a series of well-defined 

 longitudinal lines below, while the upper part is slightly concave. 



The external maxillipedes have the ischium and merus subequal in length, with 

 their outer surfaces crossed by a few indistinct lines ; the inner margin of the former 

 is convex, while that of the latter is concave above and below, with a large rounded 

 projection situated somewhat nearer the proximal than the distal end. 



The chelipedes are of moderate size, and their upper surface is denselj^ pubescent. 

 The merus has its inner and distal margin produced into a small flattened lobe which 

 overlaps the carpus ; both the carpus and propodus have the upper surface crossed by 

 numerous short and ill-defined lines, while the outer margin bears a fringe of long 

 hairs ; the inner border of the carpus is armed with a single acute tooth of large size 

 situated near the proximal end, the inner surface is hollowed out, and the lower and 

 internal margin is also provided with a tooth, which, however, is of small size ; the 

 inner border of the propodus is short and strongly curved ; the lower surface of both 

 carpus and propodus is glabrous and crossed by fine oblique lines, and the outer margin 

 of the propodus is seen from this point of view to be finely crenated ; the fingers are 

 more than half the total length of the propodus and but slightly tortuous, the inner 

 margin of the dactylus is carinated. The ambulatory limbs are short and slightly 

 pubescent, with the posterior surface of the meral joints crossed by faint transverse 



