On Fresh-water Entomostraca. 47 



bristles at the infero-posteal corners of the shell, which 

 appear perfectly smooth, and evenly rounded off. 



The eye is rather small, and located at a considerable 

 distance from the anterior edge of the head. This is also 

 the case with the ocellus, which is much smaller than the 

 eye, and occurs somewhat nearer to it than to the tip of 

 the rostrum. 



The antennulæ are rather slender and elongated, though 

 not extending beyond the tip of the rostrum, except by 

 their apical papillae, which latter are rather fully developed, 

 and of somewhat unequal length. 



The antennæ are comparatively short, and of the usual 

 structure. 



The lamellar expansion of the labrum is not very large, but 

 of the usual securiform shape, with the edge perfectly smooth. 



The tail (fig. 10) exhibits the structure characteristic of 

 the genus, being very slender and exceedingly mobile. It is of 

 a narrow conical form, tapering gradually towards the end, 

 which does not exhibit any notch or projecting corner 

 behind the base of the terminal claws. The post-anal angle 

 is well defined, and not far removed from the base of the 

 tail. The posterior edge beyond the anal orifice is armed 

 with a double low of about 20 well-defined denticles, the 

 outermost of which is placed at some distance from the tip. 

 The terminal claws are rather strong, and nearly straight, 

 each having a well-defined secondary denticle at the base, 

 and another somewhat smaller one about in the middle of 

 the posterior edge. 



Occurrence. — A solitary, but well preserved female 

 specimen of this form was found in a sample taken by Mr. 

 AVhitelegge from the Centennial Park, near Sydney. 



Archiv for Math, og Naturv. B. XVIII No. 3. 

 Trykt den 15de Juli 1896. 



