Notes on Cladocera. 81 



projection. C. reticulata has the head " obscure angulatum " in 

 front of the antennules; this is manifestly so. Finally, C. reticu- 

 lata has no fine teeth on the terminal claw. C. nitida (Schodler) 

 (= quadrangula, Leydig) has the armature of the terminal claws, 

 but is reticulated with quadrangular meshes. The name is given 

 on account of the teeth on the terminal claws. 



SPECIES 2. 

 Plate I. Figs. 3-4. 



Ceriodaphnia Consors. sp. nov. 

 Length circ. 0.5 mm. 



The head is prolonged, rounded at the apex, not angulated in 

 front of the antennules. The shell of the body is large, round, or 

 square with rounded angles, but with a more or less prominent 

 angle behind, as in the preceding species. The shell is strongly 

 marked with a reticulation of hexagonal meshes. The fornices 

 project moderately, but are rounded and smooth. The post-ab- 

 domen is broad, not narrowed toward the apex, but is obliquely 

 truncated, so that the caudal teeth lie on the lower margins. There 

 are about eight of these moderately large, recurved teeth on each 

 side. The terminal claws are large and smooth. The color is 

 transparent or opaque, passing through a reddish brown to nearly 

 black. A variety has the areas of the meshes marked by little 

 rounded prominences. Male not seen. Madison, 1877, with the 

 preceding species, in pools of tolerably clear water; not common. 



The shape of the post-abdomen distinguishes this species from 

 all but C. rotunda, Straus. It is plainly not that species, as that 

 has the shell of the head bent into a right angle below the eye, 

 and ornamented with spines. The specific name is given from its 

 habit of associating with the preceding species. I have never 

 found it alone. 

 6 



