388 Scientific Intelligence. 
It is strange that Dr. Nicholson should have overlooked my 
statements in regard to this point, except in the case of one 
species, especially as I had the pleasure of sending him my paper, 
before his first one was written ; and it is equally strange that the 
author of a text book of Zoélogy should not have been aware 
that this habit has been well-known for at least fifty years, and 
has been described by nearly all writers upon leeches. This genus 
of leeches is one of the most common in Europe as well as in 
erica, and is represented by ten or more species in England, 
where their habits are also well known. Johnston, in his Cata- 
logue of British Non-parasitical Worms, p. 50, 1865, even gives 
this habit as a peculiarity of the family. One would suppose that 
Dr. Nicholson might have had abundant opportunities, while 
living in England, to have observed this habit among the English 
species. His Clepsine sub-modesta does not appear to differ from 
young specimens of one of the common color-varieties of my 
upon the degree of activity of the animal. His MWephelis vermt- 
jformis is evidently young, and the description and figure are 
insufficient for its identification. No characters are given sufli- 
cient to separate it from the young of the common W. lateralis 
(Say), or my J. fervida from L. Superior. In color it agrees 
best with the latter. 
is Senuris Canadensis, if correctly described, does not 
belong to the genus Senuris, for in the latter the sete are never 
JSorked. This character would throw it into another family, even, 
—near Lumbriculus. The same remark applies also to the next 
species, indicated as “ Senuris sp.” His next one, “ Lumbriculus 
* 
shaped fascicles; it probably belongs to Lunbricus, or some 0 
the closely related genera. 
The only crustacean that the author attempts to name spe 
cifically is Pontoporeia affinis Lindstrom, which Mr. 8. L Smith 
racters 
genera, and the members of this group are notoriously difficult to 
determine without the most careful study. The Mysis relicta Lovén, 
leech generally remaining stationary in one during this period, with that por- 
tion of the body that covers the e niche aad moving conapantly with an un- 
dulatory motion, evidently intended to force a constant current of water over the 
