CEUSTACEA OF FRANZ-JOSEF LAND. 107 



Cape Flora, on June 4th, 21st, and July 5tli, 1897 ; and also in 

 July in West Bay, Cape Flora. The following is a description 

 of the species : — 



Description of tlie female. — Body robust, especially the cephalo- 

 thorax ; rostrum very short ; entire length from rostrum to caudal 

 f urea about '95 mm. (Jg of an inch). Antennules (fig. 9) short, 

 9-jointed ; the first two joints of moderate length and subequal, 

 the next two shorter and also subequal ; the second joint of the 

 flagellura (the fourth from the end) is equal to twice the length 

 of the preceding joint and to the combined lengths of the next 

 two, the end joint is slightly longer than the penultimate one ;. 

 the formula shows approximately the proportional lengths of all 

 the joints : — 



Proportional lengths of the joints 23 . 25 . 15 . 16 . 5 . 10 . 4 . 4 . 6 



Numbers of joints 1 2 3 46678 9* 



The posterior foot-jaws (fig. 10) resemble those of Thalestris 

 hibemica, Brady & Eobertsou, both in their form and armature ; 

 the other mouth-organs are somewhat similar to those of 

 Thalestris my sis, Claus. First pair of swimming-feet moderately 

 slender (fig. 11); terminal claws of both branches slender, and 

 not much more than half the length of the branches from which 

 they spring. Fourth pair (fig. 12) also slender; the inner 

 branches reach to about the end of the second joint of the outer 

 branches, and both are furnished on the inner margins with 

 long plumose setae. The fifth pair somewhat resemble those of 

 Thalestris hibernica, but the secondary joints are comparatively 

 rather larger and extend as far as the end of the basal joints ; 

 the basal joint bears five apical setae, while the surface of both 

 it and the secondary joint appears to be more covered with 

 extremely fine cilia (fig. 13). The caudal furca (fig. 16) are 

 elongate, the length being equal to fully twice the breadth. 



Description of the male. — The male diff"ers little from the 

 female except that the antennules are modified for grasping. 

 The inner branches of the second pair of swimming-feet (fig. 14) 

 are two-jointed, and somewhat similar in their structure and 

 armature to the inner branches of the same pair of feet in the 

 male of Thalestris hihernica. The secondary joiots of the fifth 

 pair (fig. 15) are elongate-ovate ; the inner margin is nearly 

 straight and fringed with minute hairs ; the outer margin, which 

 is slightly curved and tapers gradually towards the apex, bears 



LINN. JOUEN, — ZOOLOGY, VOL. XXVII. 9 



