332 Merrill—Structure and Affinities of Bunops Scutifrons. 
A small cervical gland is present in both young and adult 
forms. 
BIOLOGY. 
As the animal was not kept in aquaria under observation, 
little can be said of its biology. It lives in shallow water, 
among Utricularia , Millefolium , Lemiia and similar plants. It 
swims with a feeble but steady motion, already compared to 
that of Ophryoxus. To this genus, indeed, its habits closely 
correspond. 
The known range of the species is at present about 200 miles 
in a north and south direction, from Minocqua to Madison. It 
has not been found in the intermediate country. It is proba¬ 
bly very local in its distribution. In a second visit made by 
Prof. Birge to Minocqua for the express purpose of obtaining 
more material of this species, it was found only at the particu¬ 
lar spot where it was first discovered. Nor has it appeared in 
nearly forty bottles of material collected m similar localities in 
the same region. 
In Madison, it was found in one end of a ditch draining a 
marsh. It has not been found elsewhere there, although very 
careful search was made in exactly similar ditches and pools 
near by. 
The males of the species have not been found. It was hoped 
that they would appear at Madison, but the ditch rapidly dried 
up in late summer without showing the presence of males. 
SPECIES OF THE GENUS BUNOPS. 
The genus Bunops includes at present two species, Bunops 
serricaudata , Daday, and Bunops scutifrons , Birge. Daday des¬ 
cribes his species under the name Macrothrix serricaudata . * Ac¬ 
cording to Daday’s description, and more particularly his draw¬ 
ing, the two species differ from each other in but few particu¬ 
lars. The crest is present in B. serricaudata , but is serrated 
from the posterior end for about one-third of its length. The ser- 
* Daday, E., Crustacea Cladocera Faunae Hungaricae, p. 105, PI. II, Figs. 
47-48. 
