Miscellaneous. 427 
made in the Swiss lakes, from which it appears that up to the 
present time there have been found more Entomostraca than true 
pelagic animals. He then describes the results of his own researches 
upon several of the lakes. He has found nine new representatives 
of the pelagic fauna, of microscopic dimensions it is true, but, like 
the Crustacea, represented by a great number of individuals. Among 
the Protozoa he cites the four following species, two of which belong 
to new forms :-— 
Mastigophora: Flagellata—Dinobryon sertularia, Ehr. 
7 divergens, Imh. 
Peridinium tubulatum, Ehr. 
Ceratium reticulatum, Imh. 
Ciliflagellata 
Also two new species of Infusoria which live attached to Crustacea, 
namely :— 
Epistylis lacustris, Tmh. 
Acineta elegans, Imh. 
Among the Vermes, and especially in the class of Rotatoria, six 
different forms have likewise been observed :— 
Conochilus volvox, Ehr. 
Asphanema helvetica, Imh. 
Anurca longispina, Imh. 
spmosa, Imh., 
Triarthra, sp. 
Polyarthra, sp. 
In all therefore twelve species, seven of which are quite new. 
Dr. Imhof characterizes the true pelagic forms by means of the 
following two principal remarks :— 
1. The animals which are truly pelagic from their birth to their 
death always swim freely in the water, never going either to the 
shore or to the bottom of the lake, and never touching the surface 
of the water, so as to avoid coming directly in contact with the 
atmospheric air. 
2. The true pelagic animals carry their ova (with the exception of 
the winter-ege) either attached to the exterior of the body or in a 
sort of incubatory cavity until the young individual, whether imme- 
diately like its mother or subject to transformation, can quit the 
envelope of the egg or the incubatory cavity, and lead at once the 
mode of existence of an accomplished swimmer. 
The author has studied the pelagic fauna of the following lakes :— 
Zurich, Zug, des Quatre-Cantons, Egeri, Katzen, Greifen, Maggiore, 
Lugano, Como, and Garda,.—Bibl. Univ., Arch, des Sci. October 
15, 1883, p. 349. 
