1879. | Zoology. 585 
Florida, were the largest I have ever seen, one measuring forty- 
five millemetres in length—F¥% S. Kingsley. 
THE BELOSTOMA piscivorus.—Having some, stickle-backs in a 
jar of water I was surprised at finding one or two of them dead, 
though hardy. Soon afterwards, however, I saw a large water- 
bug paa seize one of these fish, pierce it with ‘its strong 
al and apparently suck the fish’s blood. — Henry Turner, Tth- 
a, N. Y. 
n STAGES OF THE OysTER.—Certain of the early stages of 
the oyster have been studied in Europe, but a complete history is 
much needed. Prof. W. K. Brooks is now engaged on this sub- 
ject at Crisfield, Maryland, where he has established the Summer 
Zoological Laboratory of the Johns Hopkins University in con- 
nection with the U. S. Fish Commission. He had succeeded 
May 2oth in artificially fertilizing the eggs, ascertaining that the 
process of segmentation occupied two hours, and that in six 
hours free-swimming ciliated embryos are produced, 
Marop Crass.—Mr. Miers has given in this paper a 
revision of the families, sub-families and genera of this interesting 
group of Crustacea. The genera enumerated number 106, and 
pensable to the student. The pages of the ‘NATURALIST are not 
the place for an extended examination of this system of classifi- 
cation, but b may not be out of e to notice a few of the 
rüsei, hypoglypha and. ea ae The genus hopes s DeHaa 
for which Dana established a separate group, is assigned to the 
neighborhood of Irachus. The placing of Cloris and Macro- 
cheira in the same section hardly seems proper, nor does the 
separation of Schizophrys and Cyclax from the neighborhood of 
ithrax and Mithraculus. The placing of Libinia and Cceloce- 
rus in different families is, we think, hardly right. A character 
Separating Mithrax and Mithrachulus which is not noticed in this 
paper is that in Mithrax the anterior sora Si of the meral joint of 
the external maxilliped is notched for the reception of the suc- 
See joints, while in Mithraculus it is entire. The generic 
he Classification of the Maiod Crustacea. By EDWARD J. Miers. (Jour 
nal of ‘Se Linnean Society of ae ees Vol. xiv, 1879.) Pages 634-673, 
pls. xu and XIII. 
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