Collembola and Thysanura of the Edinhurgh District, 225 



It would not have been surprising had one or two species 

 new to science been detected among the large number of 

 specimens tliat have passed through our hands. There are, 

 indeed, among them a few which differ in some respects 

 from typical examples of the forms under which we have 

 recorded them, but we feel satisfied there is nothing in any 

 of these differences to warrant specific separation. In this 

 group, colour and size are very variable, and even some of 

 the structural characters now so much relied on — the 

 relative length of the antennal segments, and the number 

 of teeth on the foot-claws and on the mucrones — are un- 

 doubtedly subject in many cases to more variation than has 

 generally been supposed. Careful comparison of a large 

 series of specimens from different countries and localities 

 would, we believe, show that a good many so-called species 

 are not worthy of more than varietal or at most sub-specific 

 rank. 



A large proportion of the species of this group of insects 

 subsist on decaying vegetable matter, fungi, and confervcC ; 

 but some undoubtedly feed on living plants of higher 

 orders. 



We are deeply indebted to Prof. Eeuter, Dr Schaffer, and 

 Dr Schott, the three eminent Continental authorities on the 

 Collembola, for having favoured us with their opinions 

 regarding a number of specimens submitted to them for 

 comparison with Continental types, and for other valuable 

 assistance. 



SYSTEMATIC LIST OF SPECIES. 



Order COLLEMBOLA. 



Family SMINTHURIDJE. 



Genus Sminthurus, Latrellle. 



Sminthurus fuscus (Linn.). 



This species, which is widely distributed in the Palaearctic 

 Eegion, ranging at least from Austro-Hungary to Ireland 

 and from Northern Europe to ISTorth Africa and the Azores, 

 occurring also in South America (La Plata), seems to be by 



