452 Entomostraca {Water-Fleas). 



freely in this hot bath (though their stems and leaves are plenti- 

 fully encrusted with a deposit of calcareous matter), and sporting 

 amongst the vegetation are myriads of Entomostraca, belong- 

 ing chiefly to two species, Gypris aculeata (fig. 7), and Gypris 

 strigata (fig. 6), the former, I believe, hitherto unknown in 

 Britain. Beside these there were found Gypris vidua, Gandona 

 reptans, JDaphniavetula, and Cyclops quadricomis. It is worthy 

 of remark that the two latter species were of stunted growth, 

 while all the bivalve species (Ostracoda) attained a fine develop- 

 ment. But it is not only under extreme conditions of heat, 

 cold, and drought, that these creatures are capable of existence. 

 We find at least one species which luxuriates in a brine strong 

 enough to destroy almost any other animal. This is the Arte- 

 mia salina, a species approaching in form the beautiful Clviro- 

 cephalus diaphanus before alluded to. It is found abundantly 

 in the brine-pits at Lymington in Hampshire, and it is remark- 

 able that it is only in the most concentrated brine — containing 

 four ounces of salt in the pint — that it makes its appearance. 

 It is said that even if this solution be slightly diluted by rain 

 the animal disappears. " During the fine days in summer they 

 may be observed in immense numbers near the surface of the 

 water, and as they are frequently of a lively red colour, the 

 water appears to be tinged of the same hue. ' There is nothing 

 more elegant/ says M. Joly, ' than the form of this little crus- 

 tracean; nothing more graceful than its movements. It swims 

 almost always on its back, and by means of its fins and tail it 

 runs in all directions through the element it inhabits. It may 

 be seen to mount, descend, turn over, spring forward, curve its 

 body into the form of an arch, and then rebound, and deliver 

 itself up to a thousand bizarre and capricious gambols. Their 

 feet are in constant motion, and their undulations have a soft- 

 ness difficult to describe/ . . . ' If we observe, in a small quantity 

 of liquid, the mother at the time of parturition, we see the 

 young group themselves round her body, and there is nothing 

 more pretty, more agile, more graceful than tins little troop. 

 But soon the scene changes ; one, two, or three young ones are 

 involved in the current which the motion of its fins causes, they 

 pass into the gutter situated between these organs, and from 

 thence come to the mouth of the mother. She at first disperses 

 them as being inconvenient bodies, but soon afterwards they 

 present themselves again, and pressed upon by the stiff hairs 

 which form the branchiaa, then by the papillae, lastly by the 

 jaws, they arrive at the mandibles reduced nearly to pulp, and 

 they are swallowed as any other substance would be/ " * 



Though mostly found, as has been stated, in brine pits, this 

 species also occurs in saltmarshes. The cause of its red colour 



* Baird'e Entomostraca, p. 59. 



