Ixi 



inadmissible to take this unproved assumption, and base an 

 argument upon it as if it were an established fact. 



We will next consider the facts presented by the distribution 

 of those species of Coleoptera which range from Madeira to 

 Europe, or to any of the other Atlantic islands. If their distribu- 

 tion has been effected by land-continuity, we should expect that 

 the proportion of winged and apterous species that extend their 

 range beyond the island, should not be very strikingly different 

 from the proportion that is found on the island. We do not find, 

 for example, that the proportion of the wingless Carab'i that have 

 reached our own country from the Continent by former land- 

 connection, is very different from that of the winged Cicindelce. 



Now, leaving out altogether those species which have certainly 

 been introduced by man, and grouping the remainder for con- 

 venience in six divisions, we find that the Madeiran Coleoptera, 

 which are not peculiar to it, may be classed as follows : — 



31 species of Carabidse, of which 26 are winged, 5 apterous. 



The whole fauna, however, presents the very different 



proportion of 38 winged, 43 apterous. 

 93 species of the families from the Hydradephaga to the 



Tomicidse inclusive, of which 90 are winged, 3 apterous. 



Total fauna; 220 winged, 27 apterous, 

 28 species of Curculionidse, of which 26 are winged, 2 apterous. 



Total fauna; 35 winged, 74 apterous. 

 15 species of Longicornia and Phytophaga, of which all are 



winged, none apterous. Total fauna ; 48 winged, 1 apterous. 

 20 si)ecies of Heteromera, of which 16 are winged, 4 apterous. 



Total fauna ; 28 winged, 27 apterous. 

 76 species of Staphylinidse, of which all are winged, none 



apterous. Total fauna; 109 winged, 6 apterous. 

 The totals are, for the wide-ranging species, 249 winged, 

 14 apterous = 263 ; for the whole fauna, 478 winged, 



178 apterous = 656. 



It thus appears that, in every case, an immensely smaller 

 proportion of apterous than of winged species are widely 

 distributed. If we take the totals we find that while about two- 

 fifths of the whole number of species range to other countries, 

 only about one -thirteenth of the apterous species do the same, 

 although among the strictly endemic species there are 160 



