2990 Part I11—Ninth Annual Report 
The extremity of the post-abdomen is less rounded in this species than 
in C. (Daphnia) rotunda; the test is also less strongly reticulated. ‘The 
members of this genus are danger signals from a hygienic point of view, for 
they frequent water containing decaying matter; as many as 1,400 were 
counted in a single quart of such water” (Herrick). 
? Ceriodaphnia punctata (P. E. Miiller). Pl. i. figs. 8a, 0. 
1886. Ceriodaphnia punctata, Herrick, loc. cit., p. 39, pl. A, fig. 13. 
A form of Ceriodaphnia, with the carapace finely and closely punctate, occurred in 
Loch Balnagowan. It appears to differ from C. reticulata and C. rotunda. I have 
referred it, provisionally, to C. punctata, P. E. Miiller, with which it seems to 
agree in the sculpture of the carapace and length of the anterior antenne. 
Scapholeberis (?), Schodler. 
Scapholeberis mucronata (Miller). Pl. i. figs. 2, a-c. 
1776. Daphne mucronata, Miiller, Zool. Dan. Prod., No. 2404. 
1850. Daphnia mucronatw, Baird, Brit. Entom., p. 99, pl. x. figs. 2, 3. 
1863. Scapholeberis mucronata, Schodler, Neue Beitrage zur Naturges. der Clad. 
1884. Scapholeberis mucronata, Herrick, ‘Toc. cit., p. 42, pl. ili. fig. 5., and 
1884. Scapholeberis cornuta, idem ibidem, p. 48, pl. T, fig. 6 (forma). 
S. mucronata and cornuta are apparently forms of the same species. 
In Raith Lake I find specimens both with and without the spine on the 
front of the head, and also intermediate forms with the spine very little 
developed. The free margins of the shell, the head, and the antenne 
are of a dark sooty colour. 
Simocephalus, Schodler. 
Simocephalus vetiulus (Miiller). 
1776. Daphne vetula, Miller, Zool. Dan. Prod., No. 2399. 
1785. Daphnia sima, Miller, Entomostraca, p. 91, t. 12, figs. 11, 12. 
1850. Daphnia vetula, Baird, Brit. Entom., p. 95, pl. x. figs. 1-la. 
1863. Stimocephalus vetulus, Schodler, Neue Beit. zur Naturges. der Clad. 
1884. Simocephalus vetulus, Herrick, loc. cit., p. 46. 
The shell of this species is finely and distinctly striate ; the posterior 
end is usually obliquely truncate and without a spine. It seems to be a 
widely distributed species. 
Daphnia, Miller. 
Daphnia pulex (Linné). 
1758. Monoculus pulex, Linné, Syst. Nat., 10th ed., vol. i, p. 635, No. 4. 
1776. Daphne pulex, Miller, Zool. Dan. Prod., p. 199, No. 2400. 
1850. Daphnia pulex, Baird, Brit. Entom., p. 89, pl. vi. figs. 1-3. 
1884, Daphnia pulex, Herrick, loc. cit., p. 56. 
A very common and variable species. 
Daphnia longispina, Miller. 
1785. Daphnia longispina, Miller, Entomostraca, p. 88, t. 12, figs. 8-10. 
1850. Daphnia pulex, var. longispina, Baird, Brit. Entom., p. 89, pl. vii. 
figs. 3, 4. 
1860. Daphnia longispina, Leydig, Naturges. der Daphniden. 
1884. Daphnia longispina, Herrick, loc. cit., p. 58. 
This comes very near D. pulex, and may only be a form of that species ; 
at any rate, I find specimens that appear to be intermediate between these 
two forms. 
Daphnia jardinii, Baird. Pl. i. figs. 4, 4a. 
1857. Daphnia jardinti, Baird, Edin. New Philos. Journ., vol. vi. 
