ENTOMOSTRACA. 199 



flesh, and in a few hours little but the external covering 

 was left." 



In speaking of " Alight-Lights/' I have already quoted 

 Dr. Baird's observations on some of the Entomostraca, and 

 here must mention, that having had but little opportunity 

 of investigating these little creatures myself, this part of our 

 book must take the character of a compilation more com- 

 pletely than some of the others. Dr. Baird's work on the 

 subject is so full of interest to all who appreciate the study 

 of Nature, that we trust the few extracts which will be here 

 presented from it will rather have the effect of inducing per- 

 sons to read it, than of satisfying them with what little they 

 find here. A ghiss of water from the spring will not lessen 

 a desire to visit the fountain-head. What I intend to do 

 is just to give a few extracts showing the nature and habits 

 of the Ento7iiodraca, as derived from observations, most of 

 them on living specimens in water. 



They are all aquatic ; they are covered with a shell or 

 carapace, which is either horny or coriaceous, sometimes 

 found of one piece, in other cases of two pieces, resembling 

 the valves of a bivalve shell. Their gills are attached either 

 to the feet or organs of mastication. Their feet are jointed 

 and hairy. They moult, or change their shell, as they 

 grow. 



