CRUSTACEA FROM THE FALKLAND ISLANDS. 363 



perfeon segments are extended latei-ally outwards over the side- 

 plates. The latter agree with those figured by Walker and 

 Chevreux for B. walkeri. The subacute medio-dorsal extension 

 of the last perseon segment and the fii'st two pleon segments is 

 very pronounced, as is that of the tliird pleon segment, but this 

 last is distinguished from the others by its obtuseness. The 

 second and third pleon segments have the postero-lateral angles 

 minutely acute. The telson has an extremely short division 

 between the subacute apical lobes, which reach a little beyond 

 the peduncle of the third lu-opod. In both specimens examined 

 the lobes were slightly unsymmetrical. 



The eyes are round, not crescentic as in B. gigantetts, nor large 

 and reniform as in B. ivalkeri. The first antennae agree with the 

 former only, in having no accessory flagellum ; the principal 

 fiagellum showed short filaments on the first, second, fourth, and 

 seventh articulations, and so on at each successive third to the 

 twenty-second or twenty-eighth, the total in one specimen being 

 30, in another 33. The longer second antennfe show a flagellum 

 of 46 joints, the proximal group very short, those towards the 

 end rather long, the whole flagellum longer by half than that of 

 the fii'st pair. Each mandible has an accessory plate, that on the 

 left forming five little teeth, that on the right having only two, 

 which are longer and apical instead of serial ; the third joint 

 of the palp is shorter than the second. The lower lip appears 

 to be without inner lobes. The first maxillje have four plumose 

 setae on the apical margin of the rather broad inner plate 

 second joint of the palp long. 



The first and second gnathopods are extremely similar in the 

 female, the hand oval, narrowest at the finger-hinge, the palm 

 making a continuous curve with the hind margin, its limit 

 defined by spines which the tip of the curved finger reaches ; 

 hand and finger slightly larger in the first gnathopod than in the 

 second. The fifth pera?opod has the hind margin of the second 

 joint sinuous, the greatest width of the joint being near its base. 



The first uropods have a peduncle much longer than the inner 

 ramus, which is longer than the outer, but shorter than the 

 inner ramus of the second pair, that ramus exceeding its peduncle 

 in length. The third ui'opods have the i-ami subequal, much 

 longer than their peduncle and somewhat longer than the 

 telson. 



Length of one specimen 12 mm., that of the specimen figured 

 9 mm. in its bent posture, probably about 12 nnii. if extended ; 

 it contained numerous eggs. 



Locality. Low spring tide at Roy Cove, the specific name 

 alluding to that of the place so diligently examined by Mr. Val- 

 lentin. 



Gen. PoxTOGEXEiA Boeck. 



1871. Pontogeneia Boeck, Forh. Selsk. Chi-istian. 1870, p. 193. 

 1906. „ Stebbing, Das Tierreich, vol. xxi. p. 359. 



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