PRESIDKNTIAL ADDRKSS SECTION D. 



95 



The genera, and certain of them may be regarded as sub- 

 genera by some systematists, are placed in descending order 

 according to the number of species contained therein. When the 

 numbers are etpial the genera are arranged in alphabetical order. 



Inspection of the table will at once show that passing south- 

 wards down the great continents the numbers of species of ter- 

 mites greatly increase, thus : 



N 



2< 



w 



17 



188 





55 



With one or two minor exceptions there are apparently 

 no species common to any two of the regions as above defined. 

 The large genera CaJotei'incs, Tcrmcs, and Eutcrmcs possess 

 representative species in all the main regions. It is interesting 

 to note that the most primitive of all the termites, namely. 

 Mastotennes, occurs in Australia, just as the most primitive of 

 living mammals. The peculiar genus Porotcnucs has one specie^ 

 in South America and two in Australia. 



The first described termite of the oceanic Seychelles Is. 

 was referred to a species {Eutcrmcs sal ebri thorax (Sjostedt)) 

 of Madagascar, but on the other hand the two species of the 

 Cocos Is. (namely. Lciicotcrmcs iiisularis ( Wasm.) and Arrhino- 

 termes occanicus (Wasm.)) appear to be distinct from an\- of 

 the mainland. The three species of New Zealand are Stolo- 

 termcs ruficeps (Brauer), with the nearest ally in Tasmania, 

 Calotermcs iiisularis (Walker), which is an Australian species, 

 and Calotermcs hroioiti (Froggatt) peculiar. 



We have but little direct information with regard to the 

 geographical distribution of termites in the past geological ages. 

 From the nature of the present distribution it would ap])ear 

 extremely probable that termites existed in the Secondary 

 Period. However, the earliest known undoubted fossil ter- 

 mites occur in the Oligocene, since it has been shown that the 

 fossil wings discovered in earlier formations, and formerly 

 referred to those of termites, were wrongly so detennined. 



In the Tertiary E]X)ch the main termite .genera were fully 

 differentiated, and this fact almost conclusively demonstrates 

 that termites arose at a much earlier period. Fossil Porutermes ^^^-^-—-^ 

 Hodotcrmcs and Eutcrmcs occur in the Oligocene and Miocen^'^Qi* b^ 



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