1912-13.] Pseudo-hermaphrodite Examples of Daphnia pulex. 311 
The rostrum is rather smaller than that of an ordinary female. The 
first and second trunk-limbs of both sides were dissected out and found to 
correspond exactly, in form and size, with those of an ordinary female. 
The processes projecting dorsally from the abdomen agree in general form 
with those of a normal female, but they are not quite so large. 
Fig. 2. — The aberrant left antennnle of specimen I., 
left aspect. The rostrum (R . ) is also indicated, 
x 300. 
Fig. 3. — The normal right 
antennule (A.) of speci- 
men I., right aspect, 
x 300. 
5. 
Fig. 4. — Left antennule of a male, left aspect, for comparison with fig. 2. x 300. 
A., antennule; F., flagellum of antennule; O.F., olfactory filaments; 
R . , rostrum ; S . , seta. 
The specimen is 1*95 mm. long, from the front of the head to the base 
of the spine at the posterior end of the carapace, and the maximum depth 
of the carapace is T25 mm. It is therefore rather a small example of its 
species.* 
The trunk was cut into serial sections, an examination of which shows 
* Females, bearing young in the brood-pouch, and collected in the same locality early 
in June, were found to range in length from 1*9 to 2-5 mm., and most of them were 2*2 to 
2‘5 mm. long ; the average length of ten specimens, taken at random, was 2-3 mm., and the 
average of their maximum depths 1*4 mm. The average dimensions of six males of the 
same species were— length, L45 mm. ; depth, 8 mm. 
