Myriapoda 185 



The Alpine and cave Diplopods are, of course, unrepre- 

 sented in this country. The foreign Diplopods include those 

 that come into this country on botanical specimens, vege- 

 tables &c. An example of this is the discovery of a Scutigera 

 in Scotland by Gibson Carmichael. It is not impossible that 

 this animal may really have been bred in this country, but 

 it was most probably imported. A specimen of Polyxenus 

 has been described as having been found in Phoenix Park in 

 Ireland, by Carpenter. The geographical distribution of this 

 species renders it probable that it was brought into the country 

 on some plant or shrub. 



Assuming that these animals were so imported, they 

 would be examples of what Verhoeff means by foreign 

 (fremdlinge) in his classification by habitat. 



Although Myriapods are very local in their habits and may 

 usually be found in one spot, so that one would be almost sure 

 to find Cryptops hortensis under stones or flower-pots in almost 

 any garden : or Julus terrestris under the bark of trees ; yet 

 there is no doubt that Myriapods do sometimes make migra- 

 tions in large numbers for considerable distances. 



The author before mentioned, Verhoeff, describes two 

 instances of this which are very interesting. In 1878 there 

 was a migration of Brachyjulus unilineatus in Russia, and 

 the animals were in such numbers that they actually stopped 

 a train. Their crushed bodies made the line so greasy that 

 the engine was unable to proceed. 



Again, in West Germany, in June 1890, a train was stopped 

 in the same manner by a migration of Schyzophylum sabu- 

 losum. There were two varieties of this species in this migration, 

 one known as S. bifurcatum, the other as S. punctulatum. The 

 latter, however, was in much smaller numbers. An example 

 of a more local migration is supplied by Verhoeff in the case 

 of Brachydesmus super us, which live in dry seasons beneath 

 the earth and in rainy weather are found above the ground : 

 in the latter case they make short migrations. 



The seasons at which Myriapods breed are the spring and 



