504 Heterogenetic Development in Diaptomits. [May> 



doubt that it is a new species. A complete diagnosis unfortu- 

 nately cannot be given. 



Head remarkably small and produced downward ; eye very small ; the head ex- 

 tends into a beak-like prolongation below the eye ; the antennules are very long and 

 pendant as in Moina; the body is longer than in reticulata, and the reticulations 

 have a double contour line as in C. pulchella ; the abdomen is slender and the sides 

 nearly parallel, the claws being short and truncate, the spines of the usual size. Two 

 summer eggs were in the cavity of the animal figured, 



A fifth species of Ceriodaphnia was found in cold springs near 



Tuscaloosa, Ala., which is not greatly different from C. reticulata 



as defined by P. E. Mueller and Kurz. 



Ceriodaphnia (^reticulata var.) parva, sp. (vel var.) nov. 



Tf^o~TMo ^'^' 1°"^S> transparent; head not strongly depressed, somewhat abruptly 

 angled in front of antennules; fornices not very prominent; antennules short, coni- 

 cal, shell oblong, ending in a sharp angle posteriorly, simply reticulated; abdomen 

 rather short, not narrowed very much, distally rounded at the extremity; claws 

 rather short, smooth, spines short curved. 



This very small species was found in considerable numbers, 

 but very little variation in size was noticed. C. pulchella Sars, is 

 0.5-0.6™"^, but the head is quite different, though the abdomen is 

 similar. Kurz says also, ** Die schalensculptur ist doppel-linig," 

 which is not the case in our species. 



C. quadrangula is 0.6™"^, but several iinportant differences are 

 observable between the two species. In that species the head is 

 said to be " valde depressum, ante basin antennarum ferme non 

 angulatum;" the antennules are large and the abdomen narrow. 



In general appearance this species is a reduced copy of C. 

 reticulata, but the claws are smooth. Kurz speaks of a small 

 var. oi reticulata with smooth claws, but the fornices are then said 

 to be sharp. 



Fig. 







EXPLANATION OF PLATE VII. 



1. Diaptotnus pa 



2. '* 



llidus 



, female, 

 fifth feet of female. 



3- 



<( 





fifth feet of male. 



4- 



11 





antennules. 



5- 



<< 





mandible. 



6. 



<( 





head. 



7. Canthocampius, sp. 

 8. 



n, ? fifth foot of female, 

 fifth foot of male. 



9. 







antennules. 



10. 







antenna of female. 



II. 

 12. 







spermath?eca. 

 stylets of female. 



13. 

 14. 







stylet of male, 

 maxilliped. 



