THE AUSTRALIAN NATURALIST. nLOS 
The antennae constitute the most striking feature. 
The two basal joints are closely adpressed, and appear to 
form a pedicle from which the flattened terminal lobes 
project, but on inserting a pin between them they open 
owt into two flat-sided joints. The terminal lobes. are 
clothed with an arista close to the base. I kept a number 
of the larve in a jar with some of the associated ants, but 
could not observe any attention on the part of the latter. 
I am of the opinion that the larvee feed on the eggs and 
larve of the ants, and that the ants may get in return a 
secretion from the fly larve. 
_SHORE-LINE VEGETATION OF PORT JACKSON 
DISTRICT. 
(By A. A. Hamilton.) 
(Abstract. ) 
The various agencies affecting the vegetation on the 
ocean shore-line were dealt with, showing that the factor 
most injurious to plant life in this region is the on-shore 
wind, which compresses the shrubs into a stunted horizon- 
tal growth, and sets up an unstable condition for the beach 
and dune plants by eroding and transporting the loose 
_sand. The plants adopt various devices to secure a foot- 
hold in the mobile soil by trailing, deep tap-rooting, form- 
ing a carpet, or by framing a network of underground — 
stems. i 
Two indigenous grasses, Spinifex lirsutus and Fes- 
tuca littoralis, play an important part in the building an 
upkeep of the exposed dune embankment, the Fescue per- 
forming the office of pioneer builder and the Spinifex re- — 
taining the sand collected by its hardier associate, which 
ventures out on the beach beyond the limit of other vege- 
tation. 
for sea voyaging, their coats consisting of woody, corky, 
or pithy material, primarily designed for buoyancy, and 
of a tough but yielding texture capable of resisting frac- 
ture if dashed by the waves against the rocks, when travel- 
ling, by means of the ocean currents from beach to beach. 
The lecture was supported by some admirable photo- 
graphs of the dunes, taken by Mr. Carpenter, 
The fruits of the beach plants are specially equipped Ss AY 
