STATE GEOLOGIST. 41 



mm., flagellumof the male antennae long; sensory filaments lateral, 

 also one anterior, lateral flagellum. 



Distinguished from C. quadrangula by the prominent fornices, 

 large anal ^spines, small reticulations, form of head and larger size 



A small variety resembling the above very closely is the com- 

 monest form in our larger lakes; the reticulation is commonly 

 larger but less distinct, the head is depressed and narrowed, with a 

 sinuous upper outline. The fornices are prominent and the form 

 of the post-abdomen is exactly as in the last. The spines of the 

 post-abdomen are very long and seated on small eminences. The 

 length hardly exceeds .55 mm. The claw is densely ciliated, but 

 not spined; these smaller forms have but few eggs (two). The 

 young have a thorn on the angle of the fornices. Plate J. Fig. 1 

 I'epresents the ephippial female of this species. There seems no 

 reason to doubt that this is only a variety of C. scitula. The small 

 form of C. reticulata mentioned by Kurz might be referred here, 

 while the larger form with less prominent fornices is not so diflfier- 

 €nt from the American C. dentata. 



Sp. 13. Ceriodaphnia nitida, Schcedler. 



Ceriodaphnia quadrangula, LeydiG. 



This species seems to be characterized by the quadrangular form 

 of the meshes of the shell-markings and the presence of teeth 

 «pon the claws, 



Sp. 14. Ceriodaphnia textilis, Dana. 



This species is not sufficiently fully figured to allow of a sug- 

 gestion as to its affinities. 



Daphnia rotundata, Say, is very probably a member of this 

 genus, though the description is hardly intelligible. "Body 

 rounded behind; upper antennae three-branched, a small spine 

 above at the joints; lower five-branched; color white. Length 0.5." 

 It is probable that we should read ''upper branch of antennae with 

 three setse", etc., in which case we maj' identify the above with 

 €hydorus or the like. 



III. — Genus Scapholeberis. 



The genus Scapholeberis stands rather closely related to Cerio- 

 daphnia, from which it is at once distinguished by the angled or 

 spined lower posterior angle of the shell. The head is rather 



