Descriptions of some Australian Playllopoda. 45 



The ventral margin forms along with the anterior a quite even 

 and rather strong curve. The anterior extremity is much 

 wider than the posterior and appears obtusely truncated in 

 front. Seen from above (fig. 2), the shell exhibits a rather 

 regular oval form, with the greatest width not attaining 2/3 of 

 the length and occurring in the middle, both extremities being 

 obtusely pointed. 



The surface of the valves is quite smooth and polished, 

 and in their upper part the impression for the adductor 

 muscle of the shell and the shell-gland are both plainly 

 visible. 



The enclosed animal (see fig. 5) exhibits a similar aspect 

 as in the preceding species, though differing in some particu- 

 lars rather markedly. 



Thus the head (see also fig. 6) appears comparatively larger 

 and very much curved, with the rostral projection considerably 

 more produced, and, when seen laterally, tapering gradually to a 

 very acute point. Seen in front (fig. 3) the rostrum appears 

 narrowly linguiform, with a distinctly defined notch on each 

 side of the obtusely rounded tip. 



The eyes, antennulæ, antenn æ (fig. 9), and oral parts do 

 not differ in any essential point from those appendages in the 

 preceding species, and also the legs (see fig. 12) exhibit much 

 the same structure, their number being 12 pairs as in that 

 species. 



The tail (see fig. 5) is of a similar rudimentary condition 

 as in L. macleayana, and also the lateral leaf-like lamellæ 

 issuing in front of this part would seem to be constructed in 

 the same manner as in that species. 



The ova (see fig. 5) are, on the other hand, much larger, 

 and fewer in number than in the preceding species, but, as 

 in the latter, are arranged into 2 distinct, rounded masses 

 lying within the posterior part of the shell-cavity. 



