108 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. 
As very strong evidence of our observation of the occurrence of 
sexual adults with larval characters may be noted a statement of 
Schmeil himself, who nevertheless seems to be so given to his theory 
as to be quite unable to see its bearing. Hesays: ‘‘ Nicht unerwahnt 
soll bleiben, dass zwischen den exemplaren dieser art, welche den 
Timpeln des Brockengipfels entstammten, sich eine Anzah] Mannchen 
vorfanden, bei welchen samtliche Aeste der Schwimmfiisse aus je drei 
Segmenten bestanden. Dieser Fall ist desshalb besonders interessant, 
weil hier ein Fortschreiten nach Vervollkommnung im Korperbau 
eines Tieres direct zu konstantiren ist.’? The writer is obliged to. 
confess that he cannot understand why it is not more natural to regard 
the two-jointed condition (which is common to all larve) as a retarded 
or atavistic state, from which the species tends to escape toward the 
norm under favorable condition, than to postulate an exceptional 
specific norm (which in this case is confessedly unstable), and assume 
that from some cause, utterly unknown to us, the form tends to ‘‘pro- 
ceed to a greater completeness in structure.’’ The ‘‘greater comple- 
tion”’ or realizing of its ideal —‘‘Vervollkommnung’’—implies that it- 
is incomplete or has failed to attain its specific possibilities, unless, 
indeed, the generic characters have for Schmeil a sort of metaphysical 
cogency or power over its members apart from its heredity. Thesame 
considerations apply to the antenne. The fifth feet are as in C. bicus- 
. pidatus, The form of the receptaculum is much relied on to differen- 
tiate this form, but is admitted to vary within wide limits. Length 
0.86 to1.1 mm. Motions slow. 
* Cyclops modestus Herrick. 
PLATE XXI, Fias, 1-5. 
Herrick ’83 and ’84; Marsh ’92. 
This small species, 1.0 mm. long, was first recognized in Cullman 
county, Ala., but occurs also in our lakes. The color varies, but very 
characteristic is the peculiar shining or glaucous surface of the 
strongly arched thoracic shield and the evenly curved segments of the 
abdomen. The antenne reach but little beyond the very long first 
segment; they are usually 16 jointed, but I have notes of a similar form 
in which the antenne are 17-jointed. The feet are all three-jointed 
-and armed as follows: 
First Foor. 
ex. 3 spines. ex. 1 seta. 
Outer ramus jap. 1spine, 1 seta. Inner ramus jap. 2spines, 1 seta. 
in. 3 sete. in. 2 sete. 
SECOND Foor. 
ex. 3 spines. ex. 1 seta. 
Outer ramus |i 1 spine, 1 seta. Inner ramus {fe 2 spines. 
in. 4 sete. in. 1 spine, 2 sete. 
