Copepod Fauna of the ^^Maare " of the Eifel. 295 



maarensts it bears above the outer lateral seta an obliquely 

 placed half-circlet of fine hairs. 



Besides these five Cjclopidee, a Harpactide, namely 



6. Canthocampfus minutus ?, Miill., 



belongs to tlie littoral fauna. Of this Copepod I had only 

 quite young specimens and the much injured body of a full- 

 grown animal. I therefore do not venture to refer the animal 

 in question with perfect certainty to Canth. minutus. 



The pelagic fauna of Copepoda seems to be sharply sepa- 

 rated from the littoral fauna, and is represented by two species, 

 which, however, elsewhere scarcely ever wander from the 

 shore in the larger basins, and still more seldom exclusively 

 form the pelagic fauna, as here in the Laacher See. These 

 are : — • 



7. Cyclops sfrenuus, Fisch., and 



8. Diajytomus cceruleus, Fisch., 



the latter a pretty little variety about 1*8 millim. in length. 



Although in number of species the Copepoda are abun- 

 dantly represented, the number of individuals is too small for 

 these Crustaceans to play an important part in the fauna of 

 the Laacher See. 



The examination of the material from the 



II. Gemunder Maar 

 gave four Cyclopidse, namely 



1. Cyclops strenuus, Fisch. (pelagic), 



2. tenuicornis^ Claus, 



3. agilis^ Koch, 



4. maarensiSj sp. n., 



and the Calanid, now for the first time found in Germany, 



5. Diaptomus graciloides^ Lillj. 



The first description of this species was given by Prof. 



Lilljeborg in the summer of last year *. It was, however, 



not very detailed nor illustrated with figures. In what follows 



I endeavour to fill up this deficiency to the best of my power, 



* Bull. Soc. Zool. France, tome xiii. p. 156. 



