534 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Canthocamptus, Liaptomus , and Heterocope, and 19 species, nine more 
than have been previously recorded for this district. 
Freshwater Copepods of Germany.* * * § — Dr. O. Schmeil has issued an 
appendix to his monograph on the free-living freshwater Copepods of 
Germany. It fills up some gaps in his systematic treatment of Cyclopidae 
and Centropagidse. 
Limnetic Crustacea^ of Green Lake.f — Prof. C. Dwight Marsh has 
studied the distribution of the limnetic Crustacea of this American lake 
by means of a closing dredge. The vertical distribution shows that 
there is no general movement of the whole body of crustaceans, but that 
there are individual peculiarities for each kind. So far as the crustaceans 
are concerned the horizontal distribution is not uniform, as is so often 
assumed. 
The author agrees with Hensen that exact results in plankton work 
can be reached only by an enumeration of individuals. The volumetric 
determinations are too insecure, as indeed the discrepant results of good 
observers show. He further insists that only a long continued series of 
observations on the same body of water will furnish sufficient evidence of 
the uniformity or lack of uniformity in distribution. 
Annulata. 
Structure of Sternaspis4 — Mr. E. S. Goodrich has shown that 
Yejdovskv and Rietsch were mistaken in describing Sternaspis as having; 
a completely closed excretory organ, and as having the ovary or testis 
situated in a special cavity without communication with the coelom. By 
a study of St. thalassemoides Otto, the author has shown that the cavity 
of the genital sac communicates with the body-cavity, and that the 
nephridium is provided with a small ciliated funnel and a lumen, and is 
in one region, at all events, ciliated internally. The complex granules 
of the nephridial cells are described ; they are probably excretory, but 
the nephridium is not known to open to the exterior. Experiments 
were made as to the solubility in certain reagents of the granules, cuticle,, 
ventral shield, and setae. A detailed account of the muscular system is 
also given. 
East African Polychaeta.§ — Prof. E. Ehlers reports on collections 
made by Dr. Yoeltzkow and Dr. Stuhlmann. One of the results of 
interest is that the East African and Indo-Pacific Annelid fauna has 
some forms (not cosmopolitan) in common with the Mediterranean and 
West Indian fauna. Some important synonymies are established, and 
the following new species are described : — Neottis rugosa sp. n. (Tere- 
bellidse), Sabella sulcata sp. n. (Sabellidae). 
Nephridium of Discodrilid8e.|| — Mr. J. Percy Moore has made an 
elaborate study of the Discodrilid nephridium in Bdellodrilus illumina - 
ius and related forms. He shows that the nephridial characters, like 
those of many other parts, point to an alliance between Discodrilidaa 
* Zoologica (formerly Bibl. Zool.), Heft 21, 1898 (published 1897) pp. 145-88 
(2 pis.). t Trans. Wisconsin Acad., xi. (1897) pp. 179-224 (10 pis, and tables). 
t Quart. Journ. Micr. Sci., xl. (1897) pp. 233-45 (2 pis.). 
§ Nachrichten Ges. Gottingen, 1897, Heft 2, pp. 158-76. 
[| Journ. Morphol., xiii. (1897) pp. 327-80 (4 pis.). 
