194 CoUcyc of Forestry 



\ariety spiiiirostris Faxon, Uic sinny ccnidition, according to 

 Dr. Orlinann, being characteristic of most young individuals 

 of this species. Camharus appears to be a shallow water group, 

 none being found deeper than 3J/^ feet. The usual habitat 

 for the young crawfish is a boulder or gravel bottom in 1-2 

 feet of water, and here they occur plentifully. They occa- 

 sionally seek a sand bottom but are not as abundant in this kind 

 of a habitat. The majority of individuals collected in July 

 were young and two-thirds of these were females. Identifi- 

 cations by Dr. A. E. Ortmann. 



Class Hexapoda 



order ephemerida 



Family EniEMEUiD.Ti 



Hexagenia species, nymph. Caenis lacustris Necdham, 



Heptagenia species, nymph. n. s. Nymph. See Appen- 



Baetis species, nymph. dix. 

 Caenis species, nymph. 



May-fly nymphs were more or less abundant during the 

 July field work. Earlier in the year (June) the flights of 

 these insects were reported as enormous. Dr. Adams observed 

 large areas of the lake where the surface of the water was 

 com])letely covered by the dead bodies of May-flies. At this 

 time the nymphs must be very abundant and the (juantity per 

 unit area would be much greater than was the case in July. 

 The nymphs are mostly shallow water dwellers, Hexagenia 

 and the new Ccrnis only descending to a depth of about 15 

 feet. Heplayenia is confined to the boulder areas, Ccenis to 

 the mud bottom areas. The- other genera live on a variety 

 of bottoms. The members of this order are very important 

 as food for a number of fish. Identifications by Dr. J. G. 

 Needham. 



order odonata 



Family Agrionid.e 



Enallagma species, nym|)h. Argia putrida (Hagen. 



Nymph. 



