Niciiolls — Two Neic Thrcatoicids. 
189 
Upon the dorsal surface of the large telsoii the presence of a 
deep transverse rounded depression emphasises the upturned end, 
which bears a number of setae and is flanked ventro-laterally by 
a couple of stouter s])ines on cither side (PI. XXV, fig. 1, and PI. 
XXIX, figs. 40, 41). 
While the telsoii as a whole is coiicavo-couvcx in section, this 
tii>tilted terminal part has, in cross section, the shape of a long 
ellipse. 
JiemarlvS. This, the third sul)-alpine species to be recorded from 
Eastern Australia, is in many ways intermediate between P. cnwtmUn 
and F. sliephardi. So much is this the case that when, at first, 1 
thought of the Mt. Buffalo foian rather as a variety than a species, 
I could not decide to which of the two it should be referred. I have 
not, however, l^een able to examine any examples of F. shephardi, 
and the descriptions given by Sayce (1900) and by Chilton (1916) 
arc too brief to make possible a detailed comparison between the 
two Victorian species. Judging from fSmitlUs figures (1909, PI. 12, 
figs. 1-4) the Tasuuuiiaii forms of F. australis are somewhat variable, 
and it may later become necessary to reduce P. joyiieri to the rank 
of a variety of F. australis, l)ut for the present it seems advisable 
to regard it as distinct. 
The proportion of length of pleon to that of combined cephalon 
and peraeoii is almost exactly that given by Sayce for P. shephardi, 
but this ratio, according to Chilton, holds only for the female (and, 
presumably, for the immature male) of that species. The spinous 
condition of the ventral margin of its 6th pleon segment, likewise, 
resembles closely that of P. joyneri; in the latter, too, the sutural 
line between the 6th pleon segment and telson is shorter and less 
distinct than in P. australis; in P. shepliurdi it is presumably absent, 
being neither figured nor described. The peduncle of the second 
antenna, inner lobe of the secoml maxilla, propod of first, fourth and 
seventh peraeopods in the male of P. shephardi all approximate 
closely to the condition found in P. joyneri. The pleopods of the 
former species are not described. 
Prom P. australis, the new Victorian Phreatoicid differs in its 
larger size and more robust habit, its smooth body almost free fiuni 
setae, the proportions of the pleon, the more elongated peduncle of 
the second unteniia, the condition of the spinous plate of the left 
mandible, the more setose lower lip, the tufted comlition of the 
plumose setae on the inner lobe of the first maxillae, the shape 
of the inner lobe of the second maxillae, certain details in the thiee 
posterior legs, the endopodites of the pleopods, the less spinous 
condition of the uropods, and the shape of the outline of the infeiioi 
margin of the telson. 
