44 
The South Justralian Naturalist 
Cilia my s Asperrimus — I he rough-surfaced scallop — came up from the 
dejUhs evenly clad in a dense mat of scarlet sponee. matching the common 
color of the shell, d'hc arched, llulcd. and hiich’ .scalloped edged \'alvcs fit 
r\enly at tlu' ventral margin, and. op.ming spasnmdically. one is able to view- 
all the beauty of the animal within, with its double mw of ocelli gleaming 
on the mantle edge. The hingv-line extension gi\'cs unec|ual cars to this scal- 
lop, below the larger of which m',\y be seen the byssal notch. 'I'he young 
scallops all use the byssus as an anchor, but abandon the habit later, though 
from the fact that adult C. aspernmus are frequenth' found attached to float- 
ing Inioys. jetty piles, ^e.. it is evident that the b)-ssal organs must aUvays 
be capable of service, d his shell runs tlirough tlie whole gamut ol colors, from 
the palest lemon to bright scarlet 
Pecteu Medius diiTers from the iireceding two shells in the fact of having 
a flat upper, or left vaKc. Resting on the arched riglu lower \alve. fittcen 
or sixteen prominent ribs give strength with lightness. 1 he ears arc almost 
equal, and the \'entral margin ol the shell is broadly scalloped. From a gas- 
iroiiomical point- of vie\v. this l>i\abc is something to be considered, and w^erc 
It not for the conservati\-c taste of Australians in the matter of shellfish, l\ 
medius would not have such a pcacelul existence, d he Pecten family are of 
world wide distribution, and few sandy shores do not yield some variety ot 
this beautiful and iiitcresLiug form. From a tiny bivalve, leading a free life, 
moving swiftly through the water by the rapid opening and dosing of its valves, 
and attaching itself at will to any fixed object, until it reaches adult life, 
these shells are full of interest. 
'I’HE PLANl’S OF ARID LANDS. 
By Tellurian. 
Dr. r. Cl. B. Osborn, J^rofessor of Botany in the University 
of Adelaide, has undertaken a work of national importance, in a 
scries of special investigations regarding the characters, habits, 
kc., of the plants, and plant communities of the arid areas of 
Australia. In this he is being assisted by several other workers, 
many of them being his own students. His first article is publish- 
ed in the current volume of the '‘Proceedings of the Royal Society 
of South Australia/'' and is entitled the “Ecology of the Vegetation 
of Arid Australia.^' Ecology is a special branch of botany; it 
embraces the study of living plants in their own homes and envir- 
onments. It is as distinct from the study of systematic botany as 
is tlic stud}’ of the habits and customs of the aboriginal in his tribal 
village from the investigation of his anatom}' in a museum speci- 
men. Both aspects of scientific inqury are important, but the 
stuch' of the life and habits of the living plant or animal, in its 
natural surroundings, is of much wider general interest. In the 
case under review it is also of mch greater econonic importance, 
particularly as Professor Osborn is investigating our plants in rela- 
tion to the advent of the rabbit, the grazing of sheep, &c. 
