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possible the number and distribution of the British species 

 comprised in these families. The total number of species 

 was but small, as we had only from 130 to 150 species in 

 Britain. The extreme difficulty lay in finding out the 

 correct names for these species. For this there was a double 

 cause, (1) the paucity of British species as compared with 

 the richness of the European fauna ; (2) the inadequate 

 descriptions of supposedly well-known species. To quote an 

 extreme case, we had certainly two species of AntUrax in 

 England, as against over 100 names of species in the 

 " Katalog der PaUiarktischen Dipteren " published last year ; 

 it might naturally be assumed that nothing could be easier 

 than to identify these two species which had been so 

 thoroughly well known for at least ninety years, but the 

 exact contrary was the fact. A. fenestraius of Fallen (1814) 

 had been supposed to be known to everybody as occurring all 

 over Europe, and it was not until 1869 that Loew called 

 attention to the fact that Fallen's species was apparently 

 restricted to Middle and North Europe and North Asia, while 

 at least four allied but quite distinct species occurred in 

 South Europe, as well as two others in North America. This 

 was all very well in its way, and the four new species were 

 well described, but then the question presented itself, what 

 Fallen's original and apparently well-known species might be, 

 and it was not until a most careful search brought to light 

 Zetterstedt's description in his "Insecta Lapponica," that he was 

 able to identify it with our species. Of course it might be said 

 that he could identify it by comparison with European speci- 

 mens, but he was not fond of named specimens for comparison 

 when an adequate description was accessible. That description 

 of Zetterstedt's and that description only convinced him that 

 ours was the true A. feneslratus of Fallen. So much for one of 

 our species of Anthrax ; now for the other. Soon after he 

 commenced to study our British Diptera he received from the 

 late Nicholas Cooke some specimens of a clear-winged Anthrax, 

 and being desirous of obtaining a good series so as to name it 

 with certainty, he requested Cooke to catch him a number in 

 perfect condition. Cooke did so, and sent him a long series. 

 Unfortunately he still found a difficulty in deciding upon its 



