30 AUSTRALASIAN ANTARCTIC EXPEDITION. 
Genus MAWSONELLA nov. gen. 
In outward appearance like Dactylopusia or other Thalestrida. Anterior 
antenn eight-jointed (?), endopodite of the first pair of feet longer than the exopodite, 
three-jointed, exopodite of two joints; both branches of the three following pairs two- 
jointed; fifth pair foliaceous, minute and stunted. Mouth organs as in normal Thales- 
tride. 
MAWSONELLA TYPICA, sp. nov. 
(Plate XIII, figs. 13-20.) 
Female.—Anterior antennx eight-jointed; the first three joints much stouter 
than the following ones; posterior antennz short and stout, the proximal joint undivided, 
outer ramus small, bi-articulate; endopodite of the first pair of feet elongated, three- 
jointed, the first joint short and stout, middle joint long and bearing a single marginal 
seta at its apex, third joint half as long as the preceding one, and armed at the extremity 
with two rather stout setee; exopodite scarcely more than half as long as the endopodite, 
its marginal spines rather long and slender, external margin ciliated, except on the 
distal half of the second joint; second, third and fourth pairs with both branches bi- 
articulate, distal joint much longer than the proximal one; external margins of the 
exopodites spinous and ciliated as in the first foot; fifth pair very short, the two lamine, 
subrotund, equal in length and breadth, the external branch with four short sete, the 
internal with only one seta; fureal joints of the abdomen extremely short, scarcely as 
long as broad, only about one fourth as long as the last abdominal segment. Only 
one specimen of this species was found—taken at Station 7, “45 fathoms in pack-ice.” 
Its nearest allies would seem to be Tydmanella, A. Scott, and Dactypodella, G. O. Sars, 
but the structure of the swimming feet alone suffices to distinguish it. The anterior 
antenna as shown in the Plate is almost certainly imperfect—the apical joint being 
lost. , 
Family Wyrm. 
Genus TisBE Lilljeborg, 1853. 
TISBE TENUIMANA (Gesbrecht). 
Idya tenuimana Giesbrecht, 1902, p. 38, Plate XI, figs. 8-13. 
Tisbe tenuimana Brady, 1910, p. 560, Plate LIV, fig. 2, and Text fig. 47. 
One specimen from Station 18. 
Norman and Scott in their work on the “ Crustacea of Devon and Cornwall,” 
point out that the generic name Idya instituted by Phillippi in 1843 is invalid, the name 
being preoccupied, and they revert to the term Tisbe, used by Lilljeborg in 1853. 
Genus Macuarropus Brady, 1883. 
Macuarropus Sarst Brady. 
(Plate XIII, figs 1-8.) 
Machairopus Sarsi Brady, 1910, p- 558, Text fig. 46. 
A few specimens—not more than three or four—of Machairopus Sarsi were 
found in the proceeds of Stations 1 and 18. The species was previously known only 
