THE OCCUERENCE OF THE GENUS APUS IN 
AUSTRALIA. 
BY 
Henry Tryon. 
(Read on 19th October, 1893). 
Although three species of an allied genus of entomostracou 
(Lepidurus) were known as existing in Australia, the genus, 
represented by the specimens exhibited, was an addition 
to its recorded fauna. Apus was in appearance a minia- 
ture king crab (Limulus). The Australian species measured 
2m. in length ; and, when viewed from above, presented the 
following features First, there was a large oval convex shield 
or buckler, which sloped away on each side from a median ridge. 
This had the fore border rounded and bent under, whilst the 
hind one presented a broad and deep excavation, the .sides of 
which were finely serrate. Beyond this shield the gradually 
tapermg segmented hindbody extended some distance, terminat- 
ing m two long jointed stiff filaments or styles. At about a 
ourt ot the length behind the fore border was a transverse 
^•oove, in fr-ont of which were two compound eyes. This con- 
spicuous shield was only attached to the body, which it covered, 
from the transverse groove forwards. On the under surface of 
the crustacean the antenme, or feelers, and mouth organs were 
observable, and behind these no less than sixty pairs of foliaceous, 
or eaf-hke, appendages, packed side by side, of each of which 
a Hndidar body or branchia, denotive of the re.spiratory function 
tmtaHs ^ appendages 
towards the forepart of the body were somewhat leg-like in 
cmnnuterth f n present. It had been 
ruXreLwfi ■ '^°“«tituting the head and body 
intXnH Progagated commonly without the 
P tsX^^ --ely met even in 
spots wheie the animal was exceedino-lv i.r. 
rpo-arflPfl no dDundant. It was also 
iCj^diaea as illustrating a very old 
to tho ,o.si, 
