Descriptions of some Australian Phyllopoda. 31 



Seen from the side (fig. 5) it exhibits a nearly securiform 

 shape, being produced above, at the base, to a linguiform 

 projection advancing over the distal part of the cervical seg- 

 ment. Inferiorly, it juts out into a triangular compressed 

 rostral projection, and its anterior edge forms only a slight 

 protuberance in the middle, not defined by any notch or sinus 

 either above or below. On each side, the head exhibits a 

 very conspicuous, prominent, and somewhat flexuous border or 

 fornix, originating just at the upper insertion of the mandible, 

 and crossing the lateral face of the head in a diagonal direction. 

 It reaches the anterior edge at some distance below the frontal 

 protuberance, and becomes here suddenly bent downwards, 

 terminating at the tip of the rostral projection. 



Seen from the front (fig. 6), the head appears rather broad 

 and evenly vaulted in its proximal part, but becomes suddenly 

 instricted at the place where the fornix curves down, its 

 rostral part appearing very narrow and conically pointed. 

 There is no trace of the peculiar affixing organ found in the 

 genus Eulimadia (and Limnadia) on the dorsal face of the 

 head. 



The division of the body extending behind the dorsal 

 ligament and the adductor muscle of the shell, is very volum- 

 inous, and generally more or less strongly curved in its posterior 

 part. It is divided into a number of well-defined segments, 

 20 in all, besides the tail-piece. The posterior of these seg- 

 ments project considerably dorsally, forming elevated projections 

 clothed with stifP bristles, which posteriorly gradually become 

 transformed into spines (see figs. 3 & 8). 



The tail (see fig. 8) is comparatively short and much 

 deflexed, forming, as in the preceding genus, behind 2 juxta- 

 posed lamellæ, each of which terminates below in a very 

 strong and somewhat curved spiniform projection. Along the 

 slightly concaved posterior edge these lamellæ are armed with 

 a great number of small and somewhat unequal denticles, and 



