322 . BRITISH ENTOMOSTRACA. 



preceding, viz. the great difference of size, have been 

 considered by Burmeister as strong objections to the truth 

 of Nordmann's conclusions. It is true many experiments 

 and careful anatomical investigations are still wanting to 

 establish conclusively the facts as stated by Nordmann, 

 but still the observations made by him upon one or two 

 genera leave little room to doubt the truth of the opinion 

 as regards these individuals at least. Kroyer considers 

 that the Lerneadse are at a very early age capable of 

 breeding, though it is not yet known at what stage of 

 development exactly they become so. Certain it is we 

 see, in small specimens of some of these animals, small 

 ovaries and a few eggs contained in them, whilst as the 

 females increase in size the ovaries become larger, and the 

 eggs more numerous. Burmeister affirms that the Ler- 

 neadse only propagate once, and the ovary continues to 

 increase in size, and the eggs to increase in number, till 

 they become mature, and that then the parent Lernea 

 has played her part. Kroyer doubts this ; and the op- 

 posite opinion holds better with the analogy of the other 

 Entomostracous Crustacea. But upon this point direct 

 experiments are wanting. 



The animals belonging to the Lerneadse have been 

 divided by M. Edwards into three families, according to the 

 manner in which they become fixed to their prey. Some, 

 as I have already mentioned, are attached by means of 

 the head itself, which is furnished with one or more pairs 

 of horn -shaped appendages projecting laterally; others by 

 means of long arm-shaped appendages springing from the 

 thorax, united to each other at the tip, and terminating in 

 a horny button in the centre ; a third set again are fixed 

 by the aid of stout foot-jaws, armed with strong hooks. 

 These characters afford good marks of distinction, and I 

 propose naming them accordingly : 



The first set are the Anchoraceracea ; 



The second are the Anchoracarpacea ; 



And the third are the Anchorastomacea. 



