194 Marsh—Cyclopidce and Calanidoe of Wisconsin. 
The foregoing table will give an idea of the distribution of 
the species in some of the bodies of water which I have exam¬ 
ined. Green Lake is about seven miles long and has a max¬ 
imum depth of a little less than two hundred feet. The other 
lakes—the Great Lakes excepted—are shallow. Lake Winne¬ 
bago, although a large body of water, is said to be nowhere 
more than twenty-five or thirty feet in depth. Rush Lake is 
pretty largely covered with a growth of rushes and wild rice, 
and is being gradually filled up. Lake Puckaway is an expan¬ 
sion of Fox river, is to a considerable extent covered with wild 
rice and rushes, and is very shallow. 
FAMILY CALANIDJE. 
Genus DIAPTOMUS Westwood. 
KEY TO SPECIES OF DIAPTOMUS FROM CHARACTERISTICS OF MALE. 
Antepenultimate joint of antenna without appendage, 
Fifth feet nearly equal in length, oregonensis. 
Left fifth foot shorter than right, pallidus. 
Antepenultimate joint of antenna with hyaline lamella, leptopus. 
Antepenultimate joint of antenna with appendage, 
Appendage short and blunt, sanguineus. 
Appendage as long or longer than penultimate joint, 
Terminal hook of right fifth foot broad, lateral spine 
minute, minutus . 
Terminal hook falciform, 
Lateral spine nearer outer extremity of 
joint, sicilis. 
Lateral spine stout, near base of joint, ashlandi. 
