4 W. T. CALMAN. 
end of segment. Antennal scale with outer margin straight, or, in smaller specimens, 
concave. Third maxillipeds extending to or slightly beyond end of scale. First 
legs extending a little beyond middle of terminal segment of third maxillipeds ; 
hand from nearly four to nearly five times as long as broad, terminal tooth of palmar 
edge at about one-fourth of the length of the hand from distal end. Last pair of 
legs extending forward to the tip of the antennal scale. Endopod of first pleopod 
articulating with distal inner angle of peduncle. 
Branchial system.—Five pleurobranchie on each side, on the last five thoracic 
somites ; no arthro- or podo-branchie. 
Remarks.—The ‘Discovery’ specimens differ from Dr. Pfeffer’s description, and 
from a co-typical specimen with which I have compared them, in the more slender 
form of the body, due especially to the greater length of the sixth abdominal somite ; 
in the greater length of the rostrum; in the shorter lobe on the basal segment of the 
antennule, reaching only to about the distal third of the segment, while in the typical 
form it reaches nearly to the end; and in the narrower “hand” of the first legs. 
But while each of the three well-preserved specimens in this collection differs from 
the co-type in all these points, they do so in varying degree. The differences are at 
least as important as some of those which have been regarded as of specific value by 
recent writers on the Crangonide, but I do not think that they would justify us, at 
present, in separating the form inhabiting the area explored by the ‘ Discovery ’ from 
that found in the very distant region of South Georgia. 
The following table gives some measurements, in millimetres, of the co-type of 
C. antarcticus as compared with the three most perfect specimens in the ‘ Discovery ’ 
collection. All the specimens appear to be females or immature males. 
ae ee 
£0) 
Total, Length: from back of rom ‘jack of Abdominal T n to Brentlth of 
Orbit. Orbit. Somite. Seaee “Hand.” 
C. antarcticus, co-type as fs 46°0 9°75 2°5 75 9°0 3°9 
‘Discovery,’ January 27, 1902 ie 58°0 11°75 4°75 10°0 12°5 4°9 
7 March 4,1904 2... 770 | 17°60 a 13°0 15°0 = 
35 January 22, 1902 a8 37°5 8:0 2°3 7°5 8°0 eS 
Dr. Pfeffer * was the first to draw attention to the apparent “ bipolarity ” in the 
distribution of the genus Crangon. With the exception of the very imperfectly 
known C. capensis, Stimpson, from the Cape of Good Hope, C. antarcticus is the only 
species of the genus inhabiting the Southern Hemisphere, and is widely separated from 
all the other species, which are confined to the temperate and (if Sclerocrangon be 
* Die niedere Thierwelt des antarctischen Ufergebietes. Internat. Polarf. Deutsch. Exped., ii. (1890), 
pp. 520-572. 
