478 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
determining the relationships of the genera. The Xanthidse ( Xantho - 
and Panopseus) are higher forms than Eriphia and Pilumnus. This is 
especially shown by a comparison of the second pair of antennae. Cano 
would separate Cancer and Pirimela in a sub-family Cancrinae from two 
other sub-families Eripliinae and Xanthinae. 
Hermaphroditism in the Crayfish.* — Prof. v. la Valette St. George 
describes in Astacus Jluviatilis what he terms internal hermaphroditism. 
It seems as if certain spermatogonia, “ untrue to their original destina- 
tion, may, instead of dividing into spermatocytes, grow into ova. The 
appearance at different months of the year is described, and the author 
takes occasion to discuss certain problems raised by the facts. 
Entomostraca from Orkney.f — Mr. T. Scott has a few notes on some 
freshwater, brackish-water, and marine Ostracoda new to the fauna of 
Orkney ; of the fresh- and brackish-water forms at least ten species were 
found, four of which are new to Orkney. Fifteen marine species appear 
to be new to the fauna, and it is probable that much more work could be 
profitably done there. 
Free Freshwater Copepoda. if — M. J. Richard has a somewhat 
elaborate monograph on these animals. He points out that we have not 
as yet had a complete knowledge of the test-gland of any Copepod, 
though it is found in all freshwater forms. Two parts can always be 
distinguished ; there is a sac whose walls are lined by excreting cells, 
and there is a chitinous canal of varying length, which is completely 
enveloped by a granular protoplasm which contains a number of nuclei. 
In all forms where it has been followed to its termination this canal opens 
to the exterior on the upper and inner surface of the base of the first pair 
of maxillipeds. A complete account is given of the test-gland of 
Diaptomus Castor , and it is shown that the arrangements are the same in 
a number of other species. Though the canal may differ in disposition 
in various genera, it is always the same in the species of one genus, and 
its arrangement is a good generic character ; similarity in points of 
detail are indications of zoological affinity. The canal is longest in 
species confined to fresh water, and shortest in those which live indiffer- 
ently in fresh or salt water. 
The function of the gland is the excretion of waste products, and 
these products are mainly found in the cavity of the gland in a state of 
solution ; the organ is suspended in the blood fluid, and the glandular 
part is the active part, the canal serving merely as a duct. The 
antennary gland of Copepods corresponds to the organ of the same name 
in other Crustacea ; to the test gland that of the Phyllopoda, Clado- 
cera, Argulidse, and Leptostraca. The author does not admit the 
hypothesis of Hartog that the two glands were primitively one. 
The just-named author’s account of the salivary glands of Cyclops 
viridis is very incomplete ; these organs are found in all Copepods ; 
though they vary in number there is always a single median orifice on 
the labrum. The glands are unicellular, but often of great size, and are 
ordinarily filled with slightly refractive small vesicles. They empty their 
* Arch. f. Mikr. Anat., xxxix. (1892) pp. 504-24 (1 pi.). 
f Pioc. and Trans. Nat. Hist. See. Glasgow, iii. (1892) pp. 91-100. 
X Ann. Sci. Nat., xii. (1892) pp. 113-270 (4 pjs.). 
