510 GEOLOGICAL SURVEY OF THE TERRITORIES. 
from Artemia a proper group or a subgenus of the genus Branchipus, 
like Branchipus proper and Polyartemia. Dr. Grube, nevertheless, 
gave in reference to the then known facts of Artemia a mistaken char- 
acteristic of his subgenus Artemia, saying, amongst other things, that it 
possessed six apodous segments and that the short furca was only 
bristled at the ends (»ppendicibus caudalibus brevibus, apice tantum 
setosis .... ). Relative to the number of apodous segments of the abdo- 
men, Grube repeated the statement of those authors (Joly) who in Ar- 
temia did not take into consideration the first two apoidious segments of 
the abdomen, bearing the external sexual parts. Without these two 
first apodous segments of the abdomen Artemia has really six apodous 
abdominal segments, but since the external sexual organs answer mor- 
phologically to modified limbs, we only in this sense can count in Ar- 
temia six segments of the abdomen; like Branchipus in this case it 
would have but seven and not nine segments. But Grube in this sense 
does not count six apodous segments in Artemia, as he demonstrates 
nine apodous segments for his subgenus Branchipus, and we can see 
trom the general diagnosis of the genus Branchipus (1. ¢., p. 136), that 
those segments, bearing the external genitals, were taken in with the 
apodous segments of the abdomen of his genus Branchipus, 1. e., inclu- 
sive of Artemia and Polyartemia. But, in fact (as mentioned above in 
the completed deseription of Artemia salina) the species of Artemia have 
eight apodous abdominal segments, the first two of which bearing the 
external genitals, and of which the last is nearly twice as long as the 
preceding and is homologous with the two last apodous segments of the 
species Branchipus, but the Branchipode have nine apodous abdominal 
segments, of which the first two also bear the genitals, and of which the 
last, located before the furca, is not longer, but usually shorter than the 
preceding. ! 
- In regard to the position of the fureal bristles in Artemie I have 
already stated above that in our forms of Artemia the bristles are not 
only at the end but also often on the margins of the furea, and that 
these bristles often occur also in great numbers, the furca assuming, as 
in variety b. of Artemia salina, a plate form. 
If we ask now whether all species of Branchipus really possess nine 
apodous segments, of which the two last ones are homologous with 
the prolonged last segment of Artemia, then it seems indeed to be the 
case. Only Branchipus stagnalis could form an exception. At least 
from the statements of the authors? the number of apodous abdominal 
segments (whether eight or nine) cannot be inferred with certainty, and 
I myself had not hitherto occasion to examine Branchipus stagnalis. 
Concerning the question whether all the species of the genus Artemia 
have eight apodous abdominal segments, and whether in all the last 
segment is prolonged and homologous with the last two abdominal 
1TIn my paper in Zeitschrift f. w. Zool., vol. xxv, suppletnent part, appearing under 
the title ‘‘ Ueber das Verhiiltniss der Artemia salina M. Edw. zu Art. milhausenii M. 
Edw. und dem genus Branchipus,” I must add a correction relative to the propor- 
tional length of the last abdominal segments in Branchipus. There it says: ‘‘ Branchi- 
pus has nine last apodous segments, of which the two neighboring segments show 
only a small differencein length among themselves” (1. cit., pp. 106 and 110). Lough? 
to have said: ‘“‘ Branchipus has nine apodous abdominal segments, of which the last, 
situated before the furca, is not longer but usuaily shorter than the preceding seg- 
ment.” 
2Leidig, ‘‘Ueber Art. salina und Branch. stagnalis.” Zeit. fiir w. Zool. 1851, p. 
281. Spangenberg, ‘ Zur Kenntniss von Branch. stagnalis” in Zeit. f. wiss. Zool. 
1c76. pp. 8to 9. Supplement part. Claus, ‘‘ Zur Kenntniss des Baues und der Ent- 
Mee von Branch. stagnalis und Apus cancrif.” G6ettingen, 1873, p. 14, Tab. V, 
ig. 10. 
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