On Fresh-water Entomostraca. 43 



Geu. Alonella, G. O. Sars. 



18. Alonella diaphana (King). 



Alona diaphana, King, 1, c. p. 360, PI. VIII C. 



Alonella diaphana, G. O. Sars, Add. Notes Austr. Cla- 

 docera, p. 47, PI. 5, figs. 5 — 7. 



This form, described and figured in detail by the present 

 author in the above-mentioned paper, developed in the same 

 aquarium as Alona abbreviaia, but did not occur in any 

 considerable number. It was, moreover, found in a sample 

 taken by Mr. Whitelegge from the Centennial Park, though 

 rather scarce. 



19. Alonella clathratula, G. O. Sars, n. sp. 

 (PL 6, figs. 7, 8). 



Specific Characters. — Y Shell, seen laterally, oblong 

 oval, greatest breadth in front of the middle, posterior 

 extremity narrowly truncated, with the lower corner well 

 defined, simple; dorsal margin evenly arcuate, ventral some- 

 what flexuous and convex in front. Head procumbent, pro- 

 duced to a sharply-pointed rostrum. Surface of shell very 

 distinctly sculptured, exhibiting posteriorly a rather regular 

 reticulation, anterior part of valves striated transversally. 

 Ocellus much smaller than the eye. Tail rather narrow, 

 not widening distally, post-anal angle well-marked, tip nar- 

 rowly truncated, ante-anal denticles very small, hair-like, 

 terminal claws of moderate size, each with a well-marked 

 secondary denticle at the base. Length of adult female 

 0,36 mm. 



Remarks. —This form is somewhat nearly allied to the 

 European species, A. excisa, Fisher, but differs in the more 



