508 GEOLOGICAL SUEVEY OF THE TERRITORIES. 



taken for artii'ulations. Furthermore, according to Eathke, this sijecies 

 has, besides the upper lip, no other oral parts, while S. Fischer,^ in com- 

 pleting- the description of this species, describes beside the upper lips, 

 also other oral parts (upper and lower jaws), which differ in nothing from 

 the same parts in other Artemise. luour specimens with the characters 

 of A. milhausenii, tbese parts fully correspond with the description given 

 by S. Fischer. Such a great contradiction between the authors awakes 

 , a doubt whether they had to do with the same forms, thus rendering the 

 determination of this species difficult. Likewise Rathke does not men- 

 tion in this species the existence of the posterior branchial lobes, while 

 he dwells at length upon the gill-sacs, as if the former were not existing 

 at all. But in reality Eathke jirobably did not see them at all on account 

 of their transparency. These branchial lobes exist in our specimens 

 (and those from the Krimea) with the characters of Artemia milhauscnii, 

 and S. Fischer gives an illustration of them withhisdescription of J.rfemm 

 Tioppeniana. On the contrary, in Rathke's descrii)tion there is yet a dif- 

 ference in the length of the abdomen. In our individuals w^ith the char- 

 acters of Artemia milhansenii, the i)osterior part of the body, consisting 

 of ai)odou8 segments, is longer than the whole anterior part, being to it 

 in proportion at least as eight to five ; but in the specimen described by 

 Rathke the posterior part of the body is shorter than the anterior. 

 However, we can with certainty say of Rathke's description, what length 

 the posterior jjart of the body had in the specimens described by him. 

 From his words it is to be assumed that Rathlie calls the whole posterior 

 part of these animals (without the first two apodous segments of the abdo- 

 men?) a tail. The comparative length of this tail he compares with the 

 tail (postabdomen) of the scorpions, and shows by the illustration that 

 the posterior part of the body is nearly ^ shorter than the anterior part, 

 while in the stated measurements he has such figures as surprise me 

 by their disproportion, and according to which the tail would be two 

 and a half times shorter than the anterior part of the body. The 

 latter can only be called a misprint; it remains unknown, however, 

 how the omission of oral parts (excepting the upper lips) and the 

 posterior branchial lobes can be explained in Rathke's descriptions. 

 If the degradation of this form had proceeded so far, that with them 

 these parts were not developed at all, it would have been different from 

 the form examined and more completely described by S. Fischer. S. 

 Fischer, however, calls the tail of the form examined by him, long, which 

 expression^ H. Rathke does not use, but the termination of tlie post- 

 abdomen, according to Fischer's drawings, difters from the termination 

 of this part in Rathke's drawing, not showing any broadening. It is 

 possible that Rathke and Fischer had different forms in possession, 

 whereby Rathke's form is identical with the very degraded generations 

 of Artemia salina, or corresponds with them, while Fischer's form is a 

 degraded form of the larger variety a. of Artemia salina. 



Finally, on the other hand, Grube's^ diagnosis of this species aiffers 

 from our generations with the characters of Artemia milhausenii., in 

 having on the terminal lobe (lobus tarsalis Grb.) not about 17, but about 

 25, marginal bristles; it is possible that here Grabe borrowed the num- 

 ber of bristles from Rathke's drawing, who drew on his small illustra- 

 tion about such a number of bristles, only saying in the description 



1 Milne-Edwards calls in his diagnosis the postabdomen of Artemia inilhausenii also 

 long, but does not take this expression in his diagnosis of Artemia salina. 



" "Bemerkungen iiber die Phyllopoden" in Archiv fiir Naturgesch. 1853, p. 145. 

 He correctly remarks, amongst other things, that Rathke could not have observed 

 the very tender and transparent posterior branchial lobes in so old alcoholic specimens. 



