104 XII. Karel Scháfema: 



6. Occurence of the species of Niphargus i n South 



Europe. 



On my journey in South Europe I háve found 3 forms 

 of Niphargus: 



1. On the mountain Monte Ma2:giore in Istria 

 in the height of 1100 m a form most similar to the N. ta- 

 trensis. This form lives in a very small source under the 

 rotting leaves. 



2. In a periodical source on the coast of the Vrána 

 1 a k e lives N. illidžensis f . dalmatina. Also in the springs of 

 the Bosna river inillidže near Sarajevo I háve 

 found N. illidžensis living among the Gammarus forms.*) 

 Both these forms with the form from Sesto (North Italy) 

 in my former páper (32, 33,) are related to N. ladmiraulti, 

 described by Chevreux from the wells in N a n t e s in France. 

 These forms of N. illidžensis with N. ladmiraulti^ are per- 

 haps members of a Mediterranean cycie, which has various 

 local forms. 



7. How o Id are the freshwater Gammarida? 



The freshwater Gammarida of Balkán, as those of the 

 whole Europe, belong to the fixed cycles. The members of 

 these cycles are in a certain morphological connection, which 

 is in relation to their geographical distribution. 



We can distinguish the following possibilities: 



a) Forms actively immigrating into the 

 f r e s h w a t e r f r o m t h e s e a : 



These are the forms of the cycle C ar ino gammarus pun- 

 gentiformis-thoni-scutarensis-Gammarus pungens f. carinata 

 and G. p- f. acarinata. All these forms are the youngest 

 colonists of the brackish and the fresh water. 



b) Forms, which for merly occurred very 

 often, but now they are limited only to the 

 small areals: 



Synurella ambulans are living today in the very few 



^) These Gammarus are infected by the cysticercus of. 

 Cyathocephalvs truncatus Pall.. Also plenty of trouts living there 

 were infected by the adults of Cyathocephalus truncatus Pall. 

 But the trouts are often avoiding- the infected Gammarus. 



