PACKAKD.] TRANSFORMATION OF ARTEMIA. 507 



milliausenii of the authors (exclusive of their mistakes), and likewise oc- 

 curred in it at the same time specimens of the transitory form toward 

 A. salina Milne-Edw., whose specimens here were in various dejjrees of 

 degeneration in the direction of Arlemia milliausenii. They were all 

 such specimens as those found by me at the end of summer, 1873, 

 and middle of summer, 1874, in the Kujalnitzki Lake, near Odessa, that 

 is to say, partly complete, partly not fully changed, specimens in form, 

 known under the name of Artemia milhausenii. The circumstance that in 

 the very saline Sakki Lake, there still occurred also in the middle of July ' 

 many specimens of the transitional form between A. salina and A. mil- 

 hausenii, is explained by the fact that the precediiig winter in the Krimea 

 was very snowy, that the water in the salt lake in spring became very 

 diluted, and that the specimens and generations of Artemia salina had 

 to change rapidly in one summer, therefore many specimens did not 

 succeed in fully transforming in this one summer. (Only at very gradual 

 increase of the concentration of the salt water have the following genera- 

 tions of Artemia salina in all their specimens the form of Artemia mil- 

 Jiausetiii, as observed by me in the course of several years in the Kujal- 

 nitzld salt lake near Odessa.) After several days of great drought and 

 increase in the amount of the deposited salt in the Sakki Lake, I could 

 not find a single individual of Artemia. I have to state that the speci- 

 mens of Artemia in this lake belong to those two races of Artemia sa- 

 lina, which live in the neighborhood of Odessa in the Kujalnitzki salt 

 lake. The smaller individuals of this much distributed species answer 

 to Artemia salina, changed in the known manner, but the larger indi- 

 viduals answer to variety a. of Artemia salina changed in the same di- 

 rection. 



It would here be important to know what is really wantiog in the 

 degraded generations of Artemia salina, in order to possess all the char- 

 acters of Artemia milliausenii Autorum. 



Contrary to the diagnosis -of this species {A. milhausenii of Milne- 

 Edwards), we in our generations notice but the one difference, that on 

 the female claspers of our individuals toward the middle is found a 

 small protuberance or broadening, Milne-Edwards not mentioning this 

 (of course in the females, as the males were yet unknown at that time). 

 These words of Milne-Edwards do not correspond wirh Eathke's state- 

 ments, who described this species under the name of his Artemia salina. 

 We see from Eathke's drawing and descrix)tion that the second antenuiie 

 of the female of this species has two broadenings divided by a trans- 

 verse ring, which the author regards as the two hrst joints, whereby a 

 broadening occurs near the base, another one in the middle of the an- 

 tenna, which answers the same as similar broadenings in our female 

 specimens with the characters of this species. In comparing Artemia 

 milhausenii with A. salina we must observe that in Milne-Edwards's diag- 

 noses (Histoire naturelle des crustacees, Vol. Ill) the second antennae 

 of the males of A. salina, and the second antennae of the females of 

 A. milhausenii, of which latter the males were yet unknown, have 

 been described, as already stated above. For these determiucitions in 

 both diagnoses (cornes cephaliques) Milne-Edwards omitted to give the 

 necessary explanation. 



Opposed to this the description of Eathke gives the following differ- 

 ence: He says that in this species the upper antennae are four-jointed, 

 Tvhichis very doubtful, since in the forms of this genus and in Branchipus 

 the upper antennae are not jointed, but we only observe after a number 

 of subsections similar to faint transverse rings, which should not be 



1 Midderdorf s Sibirische Reise, Vol. II, part i, pp. 155 to 156. 



