290 Part III — 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). PI. i. figs. 3a, b. 



1886. Ceriodaphnia punctata, Herrick, loc. cit., p. 39, pi. 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 antennae. 



Scapholeberis (?), Schodler. 



Scapholeberis mucronata (Miiller). PI. i. figs. 2, a-c. 



1776. Daphne mucronata, Miiller, Zool. Dan. Prod., No. 2404. 



1850. Daphnia mucronata, Baird, Brit. Entom., p. 99, pi. x. figs. 2, 3. 



1863. Scapholeberis mucronata, Schodler, Neue Beitrage zur Naturges. der Clad. 



1884. Scapholeberis mucronata, Herrick, 'loc. cit., p. 42, pi. iii. fig. 5., and 



1884. Scapholeberis cornuta, idem ibidem, p. 43, pi. T, fig. 6 (forma). 



S. mucronata and cornuta are apparently forms of the same species. 



In Kaith 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 antennae 

 are of a dark sooty colour. 



Simocephalus, Schodler. 



Simocephalus vetulus (Miiller). 



1776. Daphne vetula, Miiller, Zool. Dan. Prod., No. 2399. 

 1785. Daphnia sima, Miiller, Entomostraca, p. 91, t. 12, figs. 11, 12. 

 1850. Daphnia vetula, Baird, Brit. Entom., p. 95, pi. x. figs. 1-la. 

 1863. Simocephalus 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, Miiller. 



Daphnia pulex (Linne). 



1758. Monoculus pulex, Linne, Syst. Nat., 10th ed., vol. i, p. 635, No. 4. 

 1776. Daphne pulex, Miiller, Zool. Dan. Prod., p. 199, No. 2400. 

 1850. Daphnia pulex, Baird, Brit. Entom., p. 89, pi. vi. figs. 1-3. 

 1884. Daphnia pulex, Herrick, loc. cit., p. 56. 



A very common and variable species. 



Daphnia longispina, Miiller. 



1785. Daphnia longispina, Miiller, Entomostraca, p. 88, t. 12, figs. 8-10. 

 1850. Daphnia pulex, var. longispina, Baird, Brit. Entom., p. 89, pi. 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 jardinii, Baird, Edin. New Philos. Journ., vol. vi. 



