Vol. 34, pp. 81-84 June 30, 1921 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



THE JULIDAE AND ISOBATIDAE IN NORTH 



AMERICA. 



BY RALPH V. CHAMBERLIN. 



In contrast with the great abundance and variety of members 

 of the diplopod famihes Juhdae and Isobatidae in Europe, 

 comparatively few forms of these famihes, as now restricted, 

 have been recorded from North America, where they are ahnost 

 wholly replaced by the Parajulidae. Having recently noted 

 several European juloid species both in material taken at 

 quarantine on plants arriving from Europe and in collections of 

 estabhshed forms, I was led to suspect that we might not have 

 any truly endemic species of Julidae or Isobatidae and to review 

 the available American material in comparison with the corres- 

 ponding portion of the European fauna. As a result I find all 

 our species of these families thus far known to be in reality 

 common European forms which are still often brought across 

 the water with imported plants and other cargoes. Probably 

 all were thus artificially introduced, most of them at early dates. 

 They occur only in well-settled parts of the country and are as 

 yet rare in the Middle and Far Western States. 



The six valid species which I find to be established in this 

 country together with their synonymy and known distribution 

 here are indicated below. 



JULIDAE. 

 Genus Diploiulus Berlese. 



This is the Cyhndroiulus of Verhoeff . Irrespective of varying definitions, 

 Diploiulus must be applied to whatever generic group is made to include 

 its type species, Julus boleti C. Koch (=J. rufifrons C. Koch). As this 

 species is uniformly regarded as conforming to Cyhndroiulus, this name 

 .must give way to Diploiulus. 



15— Proc. Biol. Soc. Wash., Vol. 34, 1921. ' (81) 



