6 MICHIGAN FISH COMMISSION— BULLETIN NO. 5. 



Pine Lake is peculiarly poor in its number of species. This is strikingly- 

 apparent when we compare it with Intermediate Lake. Pine Lake was very 

 thoroughly examined, and it is likely that we are acquainted with all the 

 species occurring there, and yet the number is only eight. All the collec- 

 tions from Intermediate Lake were made in one day by a party which went 

 down from Charlevoix and remained only a few hours, and yet the number 

 of different forms is eleven. Intermediate Lake seems to be an unusually 

 rich collecting ground, for with the exception of Lake St. Clair and Bound 

 Lake, no other lake shows such a large number of species, and both Lake 

 St. Clair and Round Lake have been very thoroughly explored. Moreover,, 

 in the case of Round Lake, several of the species may be considered as 

 immigrants from Lake Michigan. 



In general it may be said that the copepod fauna of Michigan does not 

 differ materially from that of Wisconsin, which I have already described 

 in a former report. (Marsh '93.) This is only what one would expect 

 because of the very wide distribution of the species, as already noted. 

 (Marsh' 93, p. 191.) 



Inasmuch as many of the species have been imperfectly described, it 

 has seemed best to me in preparing this paper to devote some space to 

 more detailed descriptions, and particularly to furnish some figures in, 

 addition to those already published, and in this way to supplement the- 

 work of preceding papers. 



The literature of the Copepoda is so scattered that it is very difficult for 

 any one except a specialist to make determinations of species that are at 

 all satisfactory. Without doubt this fact has deterred many from attempt- 

 ing any study of the Copepoda. Much valuable work in regard to the 

 distribution of species might be done by amateur investigators if there were 

 any work giving brief directions by which the species might be determined 

 with a fair degree of accuracy. This lack, with the advice of Professor 

 Reighard, I have attempted to supply in the present paper. Preceding 

 the notes on Diapiomus and Cyclops, I have given a brief synopsis of the 

 species of those genera. These synopses, which, with some modifications,- 

 are like those in my paper on the copepods of Wisconsin, are intended 

 simply to furnish a means of recognizing the species by some of their most 

 obvious characters. While the first six plates may be considered as sup- 

 plementing the work of my Wisconsin paper, I have thought best, in 

 order to aid in the identification of species to add the seventh, which 

 repeats some of the figures of the former paper. I think that by means of 

 the synopses and plates, any one who has the patience to make the neces- 

 sary dissections, will be able without much difficulty to identify our species 

 of Cyclops and Diaptomus, at least as far as adult forms are concerned. 



I have included in the synopses some species which have not yet been 

 found in Michigan, but which have been reported from Wisconsin, and 

 will, doubtless, after a more thorough exploration, be included in the 

 Michigan fauna. 



