OSTRACODA. 691 
Krausella.] 
Family BEECHERELLID 4. 
Genus KRAUSELLA, n. gen. 
Carapace small (1.5 to 2.5 mm. in length), somewhat elongate, subelliptical, 
obscurely triangular or semiovate in outline, the dorsal margin more convex than 
the ventral, the latter straight or but gently convex; with moderately thick and 
very unequal valves; right valve the smaller, drawn out posteriorly into a strong 
spine-like process; left valve overlapping the right all around. 
Type: Krausella inequalis, n. sp. 
At present Iam acquainted with only four species that should be placed in 
this genus, viz.: the two about to be described, Bairdia anticostiensis Jones (Quart. 
Jour. Geol. Soe., vol. xlvi, p. 548; 1890) from the Hudson River or Cincinnati forma- 
tion of the island of Anticosti, and an undescribed form (near K. arcuata) which is 
rarely met with in the upper beds of the same formation in Ohio and Indiana. These 
species do not agree with Bairdia since the spine-like process is not formed by the 
tapering ends of both valves, but is restricted to the right valve, the left valve being 
rounded posteriorly and resembling the corresponding valve of a thick-shelled 
Bythocypris. We have therefore the difference that while the two valves of a Bairdia 
are similar in outline, they are quite different posteriorly in Krausella. 
The spine-like process reminds of some of the species placed by the author under 
his genus Beecherella.* If there is any true relationship between Kvausella and 
Beecherella, and I confess that I am strongly inclined to believe there is, then the 
Beecherellas were probably all described and figured in a reversed position. Another 
thing that has become more evident than formerly is that more than one generic 
type has been included under Beecherella. Considering the strongly marked peculi- 
arities of the type species, B. carinata, it seems probable that we shall eventually 
find it desirable to restrict the genus to it. 
Of B. subtumida we know only the right valve, and this is exceedingly like the 
same valve of Krausella arcuata. Still, I hesitate to say that it should be referred to 
the present genus since it may be shown that it, like B. cristata, has the posterior 
spine on the overlapping instead of the smaller valve. In the last species namely, 
the right valve seems to overlap the left, though the overlap is very slight and 
scarcely distinguishable. Should the relations of the valves (with respect to 
overlap) in these two species prove to be really the reverse of what we know to 
be the case in Krausella, a distinct generic grouping for them would probably be 
justifiable. 
* American Geologist, vol. viii, pp. 197-204, pl. 2, October, 1891. In this paper the author describes the new genus Beecher - 
ella, with six new species and one variety, all derived from the Lower Helderberg strata of New York, 
