Crustacea 237 



but appears to be less virulent in these States. The chances of 

 acquiring the disease are small, yet no one should needlessly take 

 the risk, and in any case it is highly undesirable to be bitten by 

 a tick. If those who have been in the woods will carefully ex- 

 amine their clothing and bodies on returning home at night they 

 can avoid tick bites. The ticks wander about and do not bite 

 until some hours after locating on the person. 



The scientific name of the spotted fever tick has caused a 

 great deal of discussion, and was finally referred to the Inter- 

 national Commission on Zoological Nomenclature. The findings 

 of the Commission, discussed in fourteen pages of print, were not 

 very satisfactory, but actually the case seems simple. Dr. N. 

 Banks first described the animal as Dermacentor venustus, but 

 under this name he confused two species. Dr. C. W. Stiles in 

 1908 proposed the name Dermacentor andersoni for the spotted 

 fever tick, leaving the name D. venustus for a species found on 

 sheep in Texas, which had been included by Banks. Consequently 

 D. andersoni is the name of the tick with which we are concerned. 



Trees and shrubs are frequently observed to be apparently 

 diseased, the leaves being blotched or curled, or the ends of the 

 branches distorted. Many years ago it was supposed that these 

 effects were produced by microscopic fungi, but we now know that 

 most of them can be attributed to excessively small elongated 

 mites, peculiar for having only four legs. The mites set up irri- 

 tation which results in the formation of galls. They constitute 

 a family Eriophyidae, which of late years has been intensively 

 studied in Europe, with the result of discovering a vast number of 

 species. No doubt similar discoveries await any student in 

 Colorado who will seriously devote himself to this subject. One 

 of our commonest forms is that which produces the bright red 

 blotches on leaves of mountain maple. Another makes galls on 

 willow. A third (Eriophyes rhoinus) produces gall masses con- 

 sisting of modified branches and multitudes of small, distorted 

 leaves, on the wild sumach. 



Bright scarlet mites of the genus Trombidium are often ob- 

 served walking over the ground. They are oblong, and have a 

 velvety appearance. Their young stages are parasitic on grass- 

 hoppers and other insects. Another genus of mites, Trichotarsus, 

 is parasitic on wild bees. Bryobia pratensis of Garman is a mite 



