THE CRUSTACEA OF' NEW JERSEY. 55 



Seal. These specimens are still in fair preservation. Packard is 

 rather ambiguous in his quotation from Gissler, and from the 

 paragraphs quoted it is not clear that the latter ever secured 

 Streptocephalus 'sealii in Long Island. 



Sub-Order CLADOCERA. 



The Water Fleas. 



Feet more or less leaf-like. Body enclosed in lamina of thin 

 chitine more or less, or at least latter forming sac for protection 

 of eggs. This so-called shell springs as a fold from maxillary 

 segment and conspicuously and variously formed. Young with 

 single median eye, and this sometimes lost in later life, or some- 

 times remaining as the only visual organ. Omter covering of 

 body mostly changed by frequent moults. 



Besides the single group or super-family embraced in this work, 

 members of the other group, or Gymnonicra, will likely be added 

 with future studies. 



Super-Family CALYPTOMERA. 



Body enclosed in a bivalve shell. Mandibles truncated below. 

 Maxillae distinct, spiny. Thoracic ganglia discrete. 



Key to the tribes. 



a. Five (or six) pairs of feet, anterior pair more or less prehensile and 

 destitute of branchiae. anomopoda 



aa. Six pairs of feet, similar, foliaceous, all distinctly branchiate. 



CTENOPODA 



Tribe Anomopoda. 



Five (or six) pairs of feet, -anterior pair more or less pre- 

 hensile and without branchicC. 



Two families known from New Jersey limits. 



