498 GEOLOGICAL SURVEY OF THE TERRITORIES. 
abdomen, the development of groups of spines from the above-men- 
tioned sroups of cuticular cells. However, these cuticular cells also. 
commence in free nature in fall generations of the species A. salina to 
point themselves on their tips and to elevate themselves above the in- 
tegument. To be sure under such external conditions the enlargment 
of the furea and the number of their bristles testify in these specimens 
to a lesser retention of growth than in summer at higher salt capacity 
of the water and at higher temperature. These cuticular groups 
of cells, or, in known cases, these denticular groups of spines occur- 
ring near the base of the sensory bristle on the abdomen of A. salina 
and its varieties, are homologous with the minute denticular spines 
occurring near the base of the sensory bristles on the lateral sur- 
ace of the postabdomen in both sexes of Branchipus ferox and B. 
spinosus. Concerning the large spines on the ventral surface of many 
apodous segments (from the third to the eighth) of the abdomen of the 
males of B. spinosus, they apparently represent a phenomenon inde- 
pendent of the sensory bristles and their basal denticular groups of 
spines, or both structures are so connected with each other that the 
substituted sexual characters can be connected with the sensory or- 
gans, for which we have to take the large ventral spines of certain ab- 
dominal segments of the male B. spinosus. Beside these large spines, 
occur, exteriorly of them, at the side of the segments, in the males as 
well as in the females of this species, groups of minute denticular spines, 
each with a sensory bristle. 
The last of such conspicuous characters of the variety b. of A. salina, 
approximating this form to the genus Branchipus, consists in the fact 
that the male claspers on the anterior ventrally-directed side near the 
margin between the rugose protuberances and the middle have not only 
at the sides a complex of teeth, but also that they have on these spots 
several protuberances or integumental duplicatures. It seems to me 
that those teeth occur on that spot where certain appendages on the 
inale claspers of many species of Branchipus occur. The claspers 
themselves are considerably smaller in the males of this race than in 
the species A. salina. 
Still further on a circumstance in the biology of A. salina var. b. 
points to the inclination of this form towards the species Branchipus. 
It is that the males of this variety evidently occur comparatively more 
frequently than in the other forms of Artemia. Of sixteen specimens 
brought to me indiscriminately from the Krimea, six of them proved to 
be males.! Sucha percentage of males I never met with in other species 
of Artemia, among which the males are generally rare. Near Odessa lL 
had sueceeded hitherto in finding but one female of this variety, together 
with B. spinosus in a salt-water ditch of 4° Beaumé, none of the other 
forms of Artemia occurring there. Variety b. of ae salina, however, 
lives among all forms of Artemia known to me at the lowest concen- 
tration of salt water in salt ditches, in which live also several species 
of Branchipus, some at higher, others at lower concentration of the 
salt water. This circumstance is of importance, inasmuch as in species 
of Branchipus, which do not indicate such a difference in figures as the 
species of Artemia, parthenogenesis is unknown, while it without doubt 
exists in Artemia, and in this number probably also in variety b. of A: 
salina, being yet solely on the limits of the genus Artemia. Very rarely 
1In the summer of 1876 I found in the neighborhood of Sebastopolis, in several 
salt-water ditches and smaller salt lakes of lesser salt capacity of the water, progress- 
ively developed generations of A. salina; nearly half of their number were males. 
