On some West-Australian Entomostraca. 13 
single pair of dentiform projections at the base dorsally, 
caudal plates produced beneath into strong unguiform pro- 
cesses, and each having along the dorsal edge numerous 
(from 20 to 30) denticles of unequal size, caudal claws 
slender, without any setæ at the base, but having their outer 
part distinctly denticulated along the concave edge. Colour 
dark reddish brown. Length of adult female scarcely 
exceeding 5 mm. 
Remarks.—At first I believed this form to be the 
Estheria lutraria of Brady, described by that author from 
a badly-preserved empty shell. Having however sub- 
sequently consulted Messrs. Spencer & Halls paper, I have 
been induced to abandon this opinion. Brady’s species 
is much larger, and, according to the statement of Messrs. 
Spencer & Hall, the armature of the tail is very 
different, each of the caudal plates having dorsally only 3 
or 4 short denticles, whereas in the present species there 
is a very great number of such denticles. From Estheria 
dictyon of the above-named authors, it would also seem to 
differ both in the shape and sculpture of the shell, as also 
in the armature of the tail. From both these species it is, 
moreover, distinguished by the smaller number of legs. It is 
also very distinct from Estheria Packardi Brady, described 
in detail by the present author in another paper». | 
Description of the female. 
The length of the shell of a fully adult specimen 
measures only 4.9 mm., the greatest height 3.2 mm., and the 
greatest width 2.2. This form is accordingly far inferior in 
size to the previously described Australian species. 
1) G. O. Sars, Description of some Australian Phyllopoda. 
