1 46 Zoology of Colorado 



cases wanting. The Colorado May-flies have been especially 

 studied by Dr. G. S. Dodds, formerly of the University of Colo- 

 rado. About 20 years ago Miss M. Gill and the writer published 

 an account of an interesting species, Tricorythodes explicates 

 Eaton, found near Boulder.* It is a southern insect which is 

 just able to get through its transformations and appear late in 

 the season at Boulder. Farther north, it probably could not 

 succeed. The same thing is true of the dragon-fly Archilestes, 

 which appears in Boulder in the fall. 



The Trichoptera or Caddis-flies are really related to the 

 moths, but they have hairy instead of scaly wings. The adults 

 often come to lights at night, and the larvae may be found in 

 little cases in the streams. These cases are of very diverse kinds, 

 some free, others attached to stones. Some are cylindrical, with 

 sticks, pebbles or little shells built into them. One genus (Heli- 

 copsyche) makes coiled cases resembling snails, and a distinguished 

 conchologist once made the mistake of describing one of them as 

 a new species of snail. Many Trichoptera are fossil in Colorado. 



Anopleura 



This group, as defined by Imms, is made to include the 

 Mallophaga (Biting lice or Bird lice) and the Siphunculata (Suck- 

 ing lice). The former are numerous on our birds, but the latter 

 are of more importance to man, as carriers of disease germs. 

 Dr. H. E. Ewing has recently published** a careful study of the 

 ordinary lice of man (Pediculus). The head louse and the body 

 louse have been studied by Nuttall in England, and found to 

 hybridize. They are therefore regarded as varieties of one species. 

 Ewing finds, however, that there are distinct varieties inhabiting 

 respectively the negroes, orientals, and American Indians. The 

 Crab louse (Phthirius) is a perfectly distinct animal, belonging 

 to another genus. 



There are other small groups of insects, not discussed here, 

 though of considerable scientific interest. 



♦University of Colorado Studies, III, (1906) p. 135. It was then placed in Tricorythus, 

 but in 1923 Ulmer erected the genus Tricorythodes for it. 



**Proc. U. S. National Museum, Vol. 68, Art. 19 (1926). 



