Ea 
794 THE AMERICAN NATURALIST. [VOL XXXII. 
the remaining twenty-two being recognized as varieties, or in some 
instances as mere seasonal or habitat forms. ‘Two types of con- 
temporaneous males are described for B. brevirostris, and are also 
stated to occur in B. “/jeborgit. One of the two exhibits a marked 
resemblance to the female in its secondary sexual characters, — arma- 
‘ture of the post-abdomen and structure of the antennz. The author 
suggests that this dimorphism may be serial in the life history of the 
male, representing two stages separated by a molt. 
Although the lake is a small one, it presents a number of well- 
marked faunal areas, determined largely by the nature of the 
substratum and of the vegetation. Full lists are given of the char- 
acteristic faunas, and the adaptations exhibited by their constituent 
organisms are discussed at length. We note that no mention is 
made of the pelagic habit of many Rhizopoda, and that the author 
ranks Dinobryon, Hyalodaphnia, and Diaphanosoma as tycholimnetic 
organisms — forms which in most bodies of water are typical plank- 
tonts. Attention is called to the uneven distribution of the Cla- 
docera occasioned by the influence of light. At night they are 
dispersed through the water, on cloudy days they congregate in the 
upper strata, but on bright days they gather in great swarms on the 
sunny side of clumps of Scirpus, shifting their position as the day 
advances. ‘The Copepoda and Ostracoda, on the other hand, appear 
to be indifferent to the influences of light to which the Cladocera 
show so marked a response. Cuartes A. Koroi. 
UNIVERSITY OF ILLINOIS, URBANA, ILL. 
The Embryonic Development of the Wall-Bee (Chalicodoma 
muraria Fabr.)!— Prof. Justus Carritre’s untimely death in 1894 
left his valuable study of the embryology of the wall-bee incom- 
plete. The notes and preparations of the Strasburg savant have 
been saved from oblivion by Dr. Otto Biirger, of Goettingen, and 
published in a fine quarto with thirteen excellent plates. The first 
part of the work, dealing with the formation of the germ-layers, is 
wholly the work of Carrière ; the second part, by Bürger, is based on 
Carrière’s preparations, notes, and sketches. 
The work is of peculiar interest as the latest and most complete 
account of the embryonic development of a hymenopterous insect. 
1 Die Entwickelungsgeschichte der Mauerbiene (Chalicodoma muraria Fabr.) 
im Ei, v. Dr. Justus Carrière, herausgegeben und vollendet v. Dr. Otto Bürger. 
Nova Acta, Abh. d. kaisl. Leop-Carol. Akad. d. Naturforscher, Bà. \xix (1897), 
Nr. 2, pp. 255-419, Taf. XII-XXV. 
