502 GEOLOGICAL SURVEY OF THE TERRITORIES. 



infirmity of its characters, in which, however, it diifers from the nearest 

 forms, as one species dijfers from another species^ does not represent an 

 independent or original species. At constant high or little changed 

 coiicentratiou of tlie salt water, this form is able to produce entire series 

 of 'generations with the characters of A. milhausenii, like an original 

 species. Even if the generations of our form with the characters of A. 

 mUhauseyni are qualified at a certain behavior of the surrounding element 

 to preserve their distinctive specific characters, then these generations 

 only represent a degraded and modified form of A. salina, or, indeed, two 

 closely allied forms of A. salina, of wliich one represents the changed 

 generations of A. salina., the other the changed generation, of the first 

 variety (varietas a.) of this species. 



In a short treatise in Zeitschrift f. w. Zoologie, Vol. XXV, first snp- 

 ])lementary part, I have spoken of the changes of the generations of A. 

 salina produced by heightening tlie salt-capacity of the water in nature 

 and by artificial domestication, whereby they received the species char- 

 acters of A. milliauseyiii. Without repeating the same, I will only point 

 out that, together with the modifications of the postabdomen of A. 

 salina, the other i)arts also gradually changed in the direction toward 

 Artemia milhausenii, i. e., the postabdomen became more slender and 

 longer, the female claspers narrower ; the leg-parts also changed them- 

 selves, whereby the number of bristles and fimbriate spines of the leg- 

 lobes lessened, and the gill- sacs (Clans) chang-ed from elongate to oval, 

 thus comparatively increasing their size. We obtained finally all the 

 peculiar characters of A. mi^^iausenil, as they were described by the 

 autliors. 



The specimens with the characters of A. milliausenii in the Kujal- 

 nitzki salt lake justly i-eprcsent a degraded and changed form of A. 

 salina and its first large variety («.), for that we also distinguish two 

 different forms of individuals with the characters of A. milhausenii. 

 Some correspond with the specimens of the species, others with the 

 mentioned variety of A. salina. Even if the characters of the species 

 and this variety of A. salina, tlirough degradation of their individuals, 

 become somewhat obliterated, it is nevertheless still possible to distin- 

 guish individuals originating from this or from that form. Those cor- 

 responding Avith A. salina have about 10'"" length, those of the men- 

 tioned variety are about 12'^"" in length. In the former the post-; 

 abdomen is a little shorter, and the posterior or apodous segments is 

 shorter than the double length of the anterior part of tlie body, and is 

 in proportion to it on the average as 8 to 5, but in the latter the x^osterior 

 part of the body is equal to twice the length of the anterior i)art, or a lit- 

 tle shorter, in the proportion in the latter case of 9 to 5. In both species 

 this relation moreover dei)ends upon the age of the already sexually ma- 

 ture individuals, since in already older ones the posterior part of the body 

 is longer. Moreover, the former have a less dark red color, and their 

 rounded abdominal end is somewhat broadened and as if fiattened in 

 the direction from above downward, but the latter have a more dark red 

 color and the abdominal end is less broadened, only rounded. In this way 

 the specimens of A. milhausenii have two forms, but the difference of 

 their characters is scarcely sufficMent to regard one of them as a true race 

 in relation to the oiher, and the less so, as the deviation of the indi- 

 viduals of the one or the other category on one or the other side, accord- 

 ing to age, even at the time of sexual maturity, allows some transitory 

 stages to be recognized between tliem. It is only apparent that some 

 represent a degraded form of A, salina, but that others represent a de- 

 graded form of variety a. of A. salina. It is necessary to remark, that 



