[290]

List from [Schoenherr] of Families of Curculionidum with single genus, showing no. of species & their ranges

42. 2. 2. Americas. (Camarotus)

55. 1. (Ithycerus)

86. 2. Brazil (Oxycorinus)

89. 8. X India or Senegal; Java. (Cylas)

92. 3. Malayan archipelago (Oxyrhynchus)

585. 1. (Conophorus)

631.4. X Europe N. America, New Zealand. Madag. (Dryophthorus)

(X wide ranges) (over)

7. 21 (3. average number of species in each genus

List of Families which have only a single genus showing that they have only 3 species on average in genus.

Taking the above, & adding (4) families with 2 genera each, result is,

{63. 3. Europe

{64. 3 Am. Bor. Mexico & Brazil (3 in Waterhouses list)

{87. 5.Cape & Caffria

{88. 5. Cape

7. 21

+ 11. + 37 33 40 33 70

In 9 Families having 11 genera

3.36 average species to each genus. (N.B. grand average of class being 10.17)

 

[290v]

Here we see 8/20 or 2/5 (excluding single genera) (or 2/9 if we take Families with 2 genera) with wide ranges, whereas about 7/20 of all the genera are wide ranges ie about same proportion of aberrant genera are here wandering as genera in [illeg]. In Waterhouse's list, only 8/34 have wide ranges.

N.B. all rising genera must be local (& closely allied): all dying genera, with species very distinct if they were local when large wd remain local when small; & only genera, which had become large & had died wd be small, aberrant & if they had died equally over world wd be widely distributed.