Descriptions of some Australian Phyllopoda. 25 



Dot, however, aôect the egg itself but only its envelope, which 

 is of a very firm and chitinous consistency, ^yhen prepared 

 in Canada balsam and viewed as a transparent object (fig. 10), 

 the true egg is easily traced in the centre of the envelope as 

 a perfectly globular body. 



The colour of the shell, in alcoholic specimens, is whitish, 

 with 2 very conspicuous dark brown patches on each side 

 of the dorsal face, issuing from the umbones, the 2 anterior 

 patches being much smaller than the 2 posterior, which extend 

 more or less down the sides and reach to the posterior 

 extremity. 



Description of the adult male. 



(PI. 3-) 



The length of the shell in fully grown male specimens 

 measures 11 mm., whereas the height scarcely attains 7 mm. 

 It is accordingly somewhat longer than in the female, but not 

 as high. 



When seen from the side (fig. 1), the shell exhibits a form 

 rather different from that in the adult female, being consider- 

 ably narrower and oblong oval in outline, with the umbones 

 not nearly so prominent. The dorsal margin appears almost 

 horizontal and slightly concaved, and the ventral one is more 

 regularly curved. The anterior extremity is short and evenly 

 rounded, whereas the posterior one is rather expanded, and 

 exhibits, at the junction with the dorsal edge, a distinct 

 angle. 



Seen from above (fig. 2) the shell appears still more 

 compressed than in the female, with the greatest width not 

 nearly attaining ^/s of the length. 



As in the adult female, the valves exhibit numerous lines 

 of growth, some of which are more distinctly marked, indicating 

 a somewhat periodical rate of growth. 



