312 SUMMARY OF CURRENT RESEARCHES RELATING TO 
In an additional note* the author contrasts his own results with 
those obtained by Mr. G. N. Calkins, f Calkins regarded the small 
follicles as multi-nucleated cells instead of clusters of cells, and was not 
able to assure himself of the existence of Nebenkern and nucleolus. 
Erlanger regards these differences as the result of defective method. 
The note contains also some discussion as to the true significance of the 
terms Nebenkern , archoplasm, and corps residuels ; the author proposing 
to drop the first in favour of the last. 
PacificICoast Oligochaeta.ij: — Dr. G. Eisen describes several new 
species of Benhamia, Acanthodrilus, Aleodrilus g. n., Sparganophilus , and 
Phoenicodrilus, and two new varieties of Deltania . 
Neotropical Earth worms.§ — Dr. D. Rosa describes some new earth- 
worms from the Argentine Republic and Paraguay, including a new 
genus Opisthodrilus, and new species of Ardens , Tykonus , Microscolex y 
Benhamia , Kerria , and Ocnerodrilus. 
More Earthworms in Xce.|| — Dr. E. Sekera notes the fact that he 
found eight specimens of Dendrobsena rubida in Eastern Bohemia, in 
holes within an icy crust of snow. They were living, and emerged 
lively enough. They had probably crept out on some very sunny day, 
and been frozen up before they were able to return to the soil. 
New Japanese Land-Leeches.^] — Dr. Asajiro Oka describes three 
new land-leeches forming a new genus Orobdella , to which he gives 
the names of 0. Whitmani, 0. Ijima'i , and 0. octonaria. The genus is 
especially characterised by the absence of jaws, the reduction of the 
acetabulum, the presence of two eyes, and the fact that the number of 
rings in a somite is variable, though constant for the individual species. 
These leeches occur in moist earth or under moss in mountainous 
regions, and live upon earthworms, which they swallow entire. Exter- 
nally they resemble earthworms and attain a considerable size, one 
specimen of 0. octonaria being found which had reached the extra- 
ordinary length of 27 cm. 
The paper includes an account of the anatomy of the species, and a 
discussion of the classification of the Land-Leeches. The author adopts 
that proposed by Dr. R. Blanchard (1894), and considers that Orobdella 
is most nearly allied to Lumbricobdella. 
N ematohelminthes. 
First Stages of Development in Nematodes.**' — Dr. H. E* Ziegler 
has studied Bhabditis nigrovenosa, Bh. teres, and Diplog aster longicauda 
in reference to the early stages in development. 
The movements of the two nuclei before fertilisation appear to be 
due to streamings in the ovum. According as the nuclei meet in the 
anterior end (defined as that turned towards the receptaculum seminis), 
or in the posterior end of the ovum, the head of the embryo is towards 
the posterior or anterior end of the ovum. What comes to the same 
* Tom. cit., pp. 155-8. f Journ. Morphol., xi. (1895) pp. 271-98 (3 pis.). 
| Mem. California Acad. Sci., ii. (1896) pp. 123-98 (12 pis.). 
§ Mem. R. Accad. Sci. Torino, xlv. (1896) pp. 89-152 (1 pi.). 
|| Zool. Anzeig., xix. (1896) p. 159. 
*([ Journ. Coll. Sci. Imp. Univ. Japan, viii. (1895) pp. 275-306 (3 pis.). 
** Zeitschr. f. wiss. Zool., lx. (1895) pp. 351-410 (3 pis.). 
