122 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. 
Fifth foot small, one-jointed, with three spines, of which the inner 
is large and serrate. Total length 0.8 mm., thorax 0.42 mm., abdomen 
0.38 mm., stylet 0.09 mm., antenna 0.18 mm. Egg-sacs appressed, 
with few ova. 
Cyclops aequoreus Fischer. 
PLATE XXIII, Fie. 5. 
Lilljeborg 753 (magniceps); Fischer ’60; Brady ’68, ’78 and ’91. 
Body compressed, attenuated caudad. Antenne shorter than first 
segment, stout, six-jointed, fourth and sixth segments longest. Fifth 
feet with a small basal joint and a triangular lamina bearing on the 
distal margin three spines and a seta, lateral margins ciliate. Abdo- 
men slender, first segment very long, last very short. Stylets less 
than twice as long as wide. Longest seta as long as the abdomen. 
First foot with the formula 
ex. 3 spines. ex. 1 spine. 
Outer ramus + ap. 1 spine, 1 seta. Inner ramus {0 2 spines. 
in. 4 sete. in. 3 sete. 
Length 0.85 mi. 
This species lives in salt marshes and brackish pools, and is inter- 
esting for its departure from the generic type in several particulars. 
Three species of Cyclops were found by E. Pratz in 1866 in the 
hydrant water of Munich and described as new. : 
The first of these, C. cwcus, is blind and colorless and has 11-jointed 
antenne. 
The second species, C. subterraneus, is doubtfully identified by 
Schmeil with C. bicuspidatus. 
The third, Cyclops serratus, is probably a form of C. viridis Jurine. 
Two blind species of Cyclops have been described by G. Joseph 
(82): OC. hyalinus and C. anophthalmus, but the descriptions are not 
accessible to me. | 
HETEROGENESIS AND PREIMAGO FERTILITY IN CYCLOPS, 
The present writer’s views and statements in respect to the relation 
of sexual and anatomical maturity and the influence of the environ- 
ment have given rise to a running criticism occupying many passages 
throughout the recent monograph of Schmeil, ’92. 
These criticisms are so inconsistent, and at times so contradictory 
of the author’s own observations and statements, that it is hopeless to 
attempt to answer them, especially as his notions respecting varietal 
and specific relations seem strangely obscure. Ifa plain statement of 
the position of the present writer will remove any obscurity he feels 
bound to offer it. 
