236 : General Notes. [ March, 
also numerous. Living in small tubes formed from the slime, they 
are either colorless or of an intense yellow or red color; they 
chiefly belong to the genera Chironomus and Tanypus. Acarida 
were nowhere completely absent. Vermes were richly represented, 
and chiefly by species of Lumbriculus and Scenuris. Of the latter 
Hydra. Inthe Lake of Luzerne seventy specimens of what ap- 
pears to be Asellus forelit were taken at one dredging. Here, 
again, Lumbriculids and Dipterous larvz were very abundant. 
In the Lake of Sils (Engadine), to omit many points of interest in | 
other lakes, the Hydroids appear to be especially remarkable. A 
new species is described and figured by the author under the 
name of Hydra rhetica. Of a bright red color, and often as much 
as 1% cm. in size, it gives indications of forming buds which re- 
main permanently attached to it, and so give rise to a colony. 
The male and female individuals can be easily distinguished. 
The fauna of this lake was very rich in individuals, though com- 
paratively poor in species — Four. R. Microscopic Society. 
Tue Poison AppaRATUS OF SPIDERS.—M. Jules MacLeod has 
recently published in the Belgian Archives de Biologie, the 
results of his studies on this subject. He finds that each of the 
venomous glands of spiders is formed of a pyriform sac, the walls 
of which, provided with a muscular layer, are lined within with 
an epithelium, the cavity of which serves as a reservoir of the 
poisonous fluid. From the anterior part of this sac proceeds a 
canal which opens at the end of the cheliceres, or jaws. The wall 
of this canal contains the same parts as the wall of the sac, but 
the muscular layer is there, however, either much less developed 
or absent. The secretory cells are cylindrical, arranged in a sin- 
gle layer. These cells present a different aspect according to 
their state of repose or activity; they pass from the state of ordi- 
nary cylindrical cells (repose?) to that of cup-shaped cells (activ- 
ity?) by a series of states of passage. In certain species there 
are only cup-shaped cells (Tegenaria), of which the cup, muc 
elongated, plays the role of excretory canal. 
This last form approaches the typical unicellular glands; con- 
sequently the glands whose cells presents this disposition are, 
properly speaking, compound glands (Tegenaria). 
Deep DRrEDGINGS IN THE LAKE OF TiBERIAS.—The invertebrata 
obtained by M. Lortet in these dredgings include ten species of 
Mollusca, of which three.are new to science. These are named 
by M. Locard, Unio lorteti, U. pietri, U. maris galilei. The other 
species are Unio terminalis and tigridis, Cyrena fluminalts, Neritina 
jordani, Melania tuberculata, Melanopsis premorsa and costata. The 
three latter shells give the fauna a marine appearance ; and it is to 
be considered as a transition fauna between salt and fresh water, 
the lake having probably been originally salt, and subsequently 
altered by the passage of the Jordan waters through it. Near 
