FKOM CUKLSTMAS ISLAND. 293 



abdominal segments and fiirca are 10 : 10 : 12, «. e, the genital 

 and anal segments are equal ; in the figure, however, the genital 

 segment is shown as being the longer. The most noticeable 

 difference is in the 2nd antenna, in which the spine of the 2nd 

 basal is figured as being half as long as that of the 1st basal, and 

 is said to reach to the distal margin of the joint. In my species 

 the spine of the 2nd basal is only one-third as long as that of the 

 1st, and falls short of the distal margin of the joint by half its 

 own length. 



In view of this uncertainty it seems advisable to give the 

 Christmas Island specimen a distinct name until the specific 

 chaiucters of C. amazonicus aiid C. erijthrcei(,s are more fully 

 known. 



Female (PI. XIV. fig. 5).— Length -97 mm. ; cephalothorax in 

 mid-dorsal line -58 mm. ; abdomen -39 mm. (PI, XIV. fig. 6) ; 

 projiortions of abdominal segments and furca, dorsally 21 : 23 : 28, 

 ventrally 16:22:27. Sides of cephalon parallel, Ceph. + Th. 1 

 being about twice as long as broad. Points of 3rd thoracic seg- 

 ment (PI. XIV. fig. 7) not very long (broken in my specimen), 

 with thickened margin on posterior edge. 4th thoracic segment 

 short, with sharp points. Genital segment about 1 j times as long 

 as wide, with setse on genital openings, in lateral view with a 

 small sharp hook anteriorly on ventral edge. Anal segment a 

 little longer than genital segment and slightly overlapped by it 

 dorsally, about three times as long as wide. Fui^ca slightly 

 diverging, a little longer than anal segment. Furcal rami about 

 1x10, tei'minal setfe missing. 



1st antenna six- join ted, proportional lengths of joints } ^ ^ "^ ^ ^ . 

 2nd antenna (PI. XIV. fig. 8) with spine on 1st basal very long ; 

 spine on 2nd basal short, about § as long as that on 1st basal and 

 falling short of the nearest point of distal margin of joint by 

 about half its own length. Distal margin of 2nd basal with two 

 sharp teeth. Terminal spine of 2nd antenna very strong, shorter 

 than spine on 2nd basal. 



Mouth-parts not satisfactorily made out. 

 Jointing and number of setee of swimming feet normal. 

 1st foot : exopodite with broad terminal spine, almost as lono- as 

 endopodite, with fine denticulations. 



2ud foot (PI. XIV. fig. 9) : terminal spine of exopodite almost 

 straight, with moderately coarse denticulations on outer edge and 

 two small distal serrations on inner edge (possibly an individual 

 eharacter and not specific). 



3rd foot with long slender terminal spine on exopodite, the 

 proportional lengths of joints and spine being 28 : 20 : 60 : 70. 



4th foot (PI. XII. fig, 7) : endopodite small, with two setje ; 

 exopodite slender, the proportional lengths of its joints beino- 

 approximately 6:4:5; outer edge seta on 1st joint almost 

 as long as 2nd joint, blunt process on 2nd basal joint internal to 

 endopodite. 



Proc. ZooL. See— 1911, Xo. XX. 20 



