SCIENTIFIC SUMMARY. 
225 
ZOOLOGY AND COMPARATIVE ANATOMY. 
The Crustacea of the Guf Stream . — Those of the Gulf Stream and of 
the Straits of Florida have been reported on by Pourtales. The Brachyura 
have fallen to the hands of Dr. W. Stimpson, who describes them in the 
“ Bulletin of the Museum of Comparative Zoology/’ vol. ii. number 2. In this 
important paper Dr. Stimpson gives a full list of the Brachyura collected by 
the Coast Survey dredging expeditions of 1867-8-9. Eighty-one species, 
representing forty-seven genera, are mentioned, and fifty-two of the species 
and nineteen of the genera are described as new. More than half the species 
belong to the Maioidea , while the Ocypodoidea are represented by only two 
species, both of them belonging to the Cardnoplacidce. Only a small pro- 
portion of the species are from great depths, and the number of new forms 
seems largely due to the thorough exploration of the shallower waters. 
But fifteen species are recorded as coming from below 100 fathoms, and of 
these eleven are Maioids, and the other four are Cancroids — a Pilumnus, two 
species of Bathynectes (a new genus allied to Portunus ), and a species of 
Achelous. The greatest depth at which any of the species were found is 150 
fathoms ; and it is quite remarkable that the only species from that depth 
were Portunidce — one of the species of Bathynectes and the Achelous. 
The Life-History of Monads . — One of the ablest and longest papers we 
have seen on this subject and in English, is by Dr. Henry Fripp, in the 
il Proceedings of the Bristol Naturalists’ Society.” It is very long, and refers 
to a plate, but there is none accompanying the paper. It is to be hoped that 
it will be properly published before long, with the plate accompanying it. 
The Representation of the Melolontha vulyans in Canada — Mr. Ritchie, 
writing in a late number of the “ Canadian Naturalist,” says that the Melo- 
lontha vulgaris of Europe is represented in Canada by Lachnosterna fusca , 
commonly called the May bug. In reference to the appearance of this 
creature, we may state that it occurs in immense numbers every three 
years ; at least, such is the experience since 1855. The years 1858, 1861, 
1864, and 1867 are those when this insect appeared in greatest numbers. 
It must not be inferred from the above statement that no examples of these 
insects occurred in the intervening years, for it is always a common species 
in Canada. But there are years when certain species prevail in such 
numbers as to be noticed by everybody. One reason why the cockchafer 
should be tri-yearly may be owing to the circumstance that it remains in 
the larva state for three years. Here, then, an opportunity occurs for 
testing some of the alleged practical uses to which these insects may be 
put. 
Crustacea of the genus Libinia. — In the Philadelphia Academy of Sciences 
(“ Proceedings,” Sept.) Mr. T. Hall Streets states, in respect of the above, 
that much uncertainty has existed with regard to the identity of certain 
species belonging to the genus Libinia. Libinia dubia, ever since it was 
first established by Milne Edwards, has been regarded as a doubtful species. 
In the description of it by Edwards, he states that it resembles L. canalicu- 
lata very much, and that it is not improbable that it is the young of that 
species. Naturalists in this branch of science down to the present time 
appear to have accepted this statement as the truth. De Kay, in his 
