8 
AUSTRALASIAN ANTARCTIC EXPEDITION. 
Localities. 
4th January, 1914. Tow-net at 5 fathoms, twenty-two specimens, 7-12 mm. 
10th January, 1914. Tow-net at 100 fathoms, 2 ? and 1 $ , 22-25 mm. 
Both these tow-nettings were taken during the cruise along the pack-ice westward 
from Adelie Land to Davis’ Sea. 
21st January, 1914. Lat. 66° 47' 21" S., long. 93° 14' E., off Drygalski Island, 
tow-net at 20 fathoms, twenty-eight specimens, 7-16 mm. 
Nearly all these specimens are badly damaged, and very few retain any of the 
thoracic limbs. Their identity is, therefore, a matter of some doubt. In the gatherings 
made on 10th January, 1914, and 21st January, 1914, there are adult males and their 
copulatory organs on the first pair of pleopods agree with those figured by Hansen 
(1913) as characteristic of this species. For the remainder, I have relied on the length 
of the upper flagellum of the antennules (in such specimens as still retain them), which 
is shorter than the combined length of the last two joints of the antennular peduncle, 
to separate them from T. vicina, and the proportionate length of the last segment of 
the abdomen to distinguish them from T. gregaria. 
From measurements which I have made on fifty specimens, I find that, taking 
the length of the last abdominal segment as unity, the combined length of the fourth 
and fifth segments varies between -94 and 1 06. 
In the gathering made on 4th January, 1914, I found one specimen, 10 mm. 
long, which still retained its long legs. In this specimen, the fifth joint of the long 
legs was 2-6 times as long as the combined sixth and seventh joints. In the same 
bottle there were nine loose legs of the first pair, and measurements made on these 
show that the fifth segment varies from 2 12 to 2-64 times as long as the combined 
sixth and seventh joints. This variation, however, is one of age. In the smaller 
limbs the fifth joint is relatively shorter than in the larger limbs, and this joint evidently 
becomes more elongated as the animal grows. In adult T. vicina, about 12 mm. in 
length, the fifth joint of the long leg is about twice as long as the combined sixth and 
seventh joints (fide Hansen, 1913, plate VI, fig. 2c.). In T. macrura, 10 mm. the pro¬ 
portion is already 2-6 to 1 while, in a loose leg, which to judge from its size belonged to 
a specimen about 7 mm. long, the proportion is already 2T2 to 1, i.e., of the proportions 
of adult T. vicina. In fully grown T. macrura the fifth joint of the long leg is from 
3 5 to 3-8 times as long as the combined sixth and seventh joints (fide Tattersall, 1908, 
plate III, fig. 8 and Hansen, 1913, plate VI, fig. 3c.). Consideration of these measure¬ 
ments has led me to refer all the present specimens to T. macrura, and this identification 
is supported by the form of the first pleopods of such adult males as there happen to 
be present. 
