Entvmostraca from Jerusalem. 375 



Branchipus eximius. 

 Esther in g ih oni. 

 Daphnia Atkinsoni. 

 Cypris celt tea. 

 Gyp ris or le n ta lis. 

 IHaptomus similis. 



The only additions I have ever observed were a Cyclops 

 and several Planarice. 



The habits and movements of these Entomostracou* Crus- 

 tacea are most interesting to watch, especially the larger 

 forms. Branchipus, which closely resembles our British 

 Chirocephalus, from which it differs chiefly in the morphology 

 of its cephalic horns or prehensile organs, swims, like Chiro- 

 cephalus, upon its back, and, when shaded from a strong 

 light, may be seen balancing itself near the surface by means 

 of its numerous branchial feet, which are in constant motion. 

 On the least disturbance, however, it strikes the water 

 rapidly with the tail from right to left, darts away like a fish, 

 and will often dive to the bottom to conceal itself in the 

 soft mud. They are white and semitransparent, with the 

 compound stalked eyes conspicuous as large black dots. The 

 elegance and ease of their movements are very attractive, the 

 male especially, which is somewhat larger than the female, 

 with its singular curved horns lying forward on its thorax 

 as it bends for a spring, and then suddenly straightening its 

 body, glides along — the uninterrupted undulatory motion of 

 its branchial feet gracefully waving like a tiny cornfield in 

 the summer breeze — forms a charming study. Neither 

 Branchipus nor the other forms seem dependent upon vege- 

 table diet — at any rate, there is no plant-life in their native 

 pool, unless it be some minute Confervas invisible to the 

 naked eve, and 1 have never detected any diatoms under the 

 microscope. They seem, however, to derive their nourish- 

 ment from the mud. It is pretty to watch the Branchipus 

 use its prehensile horns like a pair of calipers to seize a mass 

 of it, which raises a dense cloud in the water ; then, turning 

 on to its back, the undulating branching form a current flowing 

 along the sort of canal between them and leading to the 

 mouth. M. Joly, in describing its congener, Artemia salina, 

 says that the mother, surrounded by her newly-hatched brood, 

 not unfrequently sweeps some of her own young into her 

 omnivorous jaws by a similar process. This cannot happen 

 to Branchipus, inasmuch as the brief existence of the indi- 

 vidual never allows of the mother living to see her offspring.. 



26* 



