On some West-Australian Entomostraca. 5 
Phyllopoda. 
Trib. Notostraca. Fam. Apodidæ. 
Gen. Apus, Schæffer. 
1. Apus australiensis, Spencer & Hall. 
(Pl. 1). 
Apus australiensis, Spencer & Hall, Report on the 
Horn Expedition to Central Australia. Part II. Zoology. 
Crustacea, p. 235, Pl. 20, figs. 1—3. 
Å single specimen of an Apus, which in all probability 
is referable to the above-named species described by Messrs. 
Spencer & Hall, developed in one of my aquaria, and was 
watched for nearly a month. On Plate 1 is given a figure 
(dorsal aspect) of the specimen in its most advanced state, 
drawn from life, and accompanied by some detail drawings. 
On comparing this figure, which has been carefully verified 
by a renewed examination of the preserved specimen, with 
that given by Messrs. Spencer & Hall, several rather striking 
differences may be found to exist, both as regards the form 
of the carapace, and the several proportions given by the above- 
named authors; and, indeed, these differences might lead one 
to suppose, that in reality it belonged to a different species. 
Considering, however, the great variations in these respects 
found in different specimens of the same species, especially 
when examined in a preserved state, I am unwilling to lay 
any stress on such characters as specific marks. The spe- 
cimen was of rather small size, as compared with those 
