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170 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. “¢ 
* Ceriodaphbnia alabamensis Herrick. 
PLATE XLII, Fie. 2. 
(American Naturalist, May, 1883. Pilate V, Figs. 11, 12.) 
This species was seen but once and is insufficiently known. The 
body is elongate, quadrate, the shell reticulated with double contour 
lines, the head very small and produced downward below the eye, 
which is very small, the antennules are longer than in any other spe- 
cies, obviously two-jointed, with a lateral seta; the antenne are very 
long; post-abdomen long and rather narrow, with the margins nearly 
parallel, truncate at the end, with over nine anal spines; claws 
smooth, abruptly truncate. My drawing represents a daphnia-like 
set of processes for closing the brood cavity. Length 1.0 mm. 
Tuscaloosa, Ala. 
* Ceriodaphnia reticulata Jurine. 
PLATES XLI, Fiaes. 15, 21; XLII, Fie. 3; XLII, Fie. 3; XLIV, Fias. 3, 4. 
Monoculus reticulatus—J urine. 
Daphnia reticulata—Baird, Leydig. 
Ceriodaphnia quadrangula—Schoedler. 
Ceriodaphnia fischeri—Ley dig, Schoedler, etc. 
Head long, obscurely angled in front of the antennules; fornices 
very prominent; antennules small; post-abdomen of moderate size, 
rounded at the end, slightly tapering; about eight long anal teeth; 
terminal claws with a series of sharp spines at the base. The reticu- 
lations are sharp but simple. The flagellum of the male antennule is 
either straight or moderately curved. Kurz says that some varieties 
have the fornices blunt while others are sharp. I have seen only the 
blunt form, which is then much like the next. 
[* Ceriodaphnia dentata Birge. | 
This form differs from the above only in having the inside of the 
claws fringed with minute bristles (sometimes absent), the angle of 
the head being more marked and the fornices less prominent. It is 
difficult to say whether our Minnesota specimens most resemble this 
or the typical C. reticulata of Europe. They seem intermediate, some 
having fornices with an abrupt angle. It may be instructive to quote 
Kurz on the European C. reticulata: ‘‘ Examples occur 0.8 to 0.9 mm. 
long, others on the contrary only 0.5 to 0.6 mm. long and combining 
with the smaller size some differential characters. In the larger va- 
riety I found the fornix obtuse, while in the smaller it extends ina 
Sharp thorn directed upward and outward. In this small sub-species 
