ENTOMOSTRACA OF THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 311 



what triangular in its general outline, and both the inner and outer margins taper to 

 the narrow distal extremity. 



In the fifth pair, the inner portion of the basal joint, which is moderately produced, 

 is transversely truncated, and furnished with about five apical setae ; the second joint is 

 broadly ovate and is provided with six setae ; the three setae on the inner margin, and 

 one near the end of the outer margin, are tolerably stout, but the other two are 

 somewhat slender. Caudal rami very short. 



Habitat. Scotia Bay, South Orkneys; collected in June 1903; Station 325, 

 60 43' 42" S., 44 38' 33" W. 



Dactylopusia ferrieri, new species. (PI. XII. figs. 14-22.) 



Female. Body tolerably stout and elongated ; rostrum short ; abdomen somewhat 

 reflexed ; caudal rami short (fig. 14). Length about I mm. 



Antennules short, scarcely reaching to the end of the first cephalothoracic segment, 

 and apparently composed of seven joints, but the articulation between the fifth and 

 sixth joints is not very clearly defined ; the first and second joints are moderately 

 robust ; the third is narrower than the second, and equal to about one and a half times 

 its length ; the other joints are small and subequal, except the sixth, which is scarcely 

 half the length of the one that precedes it ; the antennules are tolerably setiferous, and 

 the third joint bears an extremely long sensory filament (fig. 15). 



Antennae, as in Dactylopusia frigida. 



Maxillipeds small ; the first pair are each armed with a stout terminal claw, and are 

 also provided with two small marginal setiferous lobes, as shown in the figure (fig. 17) ; 

 second pair narrow and elongated, and furnished with slender terminal claws that 

 reach beyond the middle of the joints to which they are articulated (fig. 18). 



The first pair of thoracic legs have both rami tolerably stout ; the first joint of 

 the inner ramus, which is elongated and reaches nearly to the extremity of the outer 

 ramus, bears a moderately stout seta near the middle of the inner margin ; the end 

 joints are very small, and bear stout, terminal, claw-like spines, as shown in the figure 

 (fig. 19) ; a stout setiferous spine springs from the outer margin of the first and second 

 joints of the outer ramus, and the second joint has also a seta on the inner margin ; 

 the end joint of the outer ramus is very short and carries a tolerably stout setiferous 

 spine on the outer margin ; it is also furnished with two terminal claw-like spines 

 and two slender and elongated setae the inner one being considerably longer than 

 the other ; both rami are fringed on their outer margins with small bristles, and 

 stout setiferous spines spring from the distal end of both the outer and inner margins 

 of the second basal joint (fig. 19). 



The second, third, and fourth pairs are somewhat similar in structure to the same 

 appendages in Dactylopusia brevicornis (Glaus), except that the second joint of the 

 inner ramus of the second pair is provided with two setae on the inner margin, while 

 the same joint in the third and fourth pairs bears only one seta. In the third pair, 



(BOY. soc. EUIN. TRANS., VOL. XLVIII., 557.) 



