14 SOUTH-AFRICAN BUTTERFLIES. 
may be in other respects), has been generally adopted ; and although 
not satisfactory — the greater of the two divisions being founded on a 
negative character — it is undoubtedly preferable to the older arrange- 
ment into Diurna, Crepicscularia, and JYocturna, which were mere equi- 
valents of the original Linnsean genera, Fapilio, Sphinx, and PJialmna. 
The English terms, Butterflies and Moths, exactly correspond to these 
two Sub-Orders of Bhopalocera and Heterocera. The name 'Rhopalocera 
has been objected to on the ground that some Butterflies have no 
actual club or knob to the antennae ; but these exceptions are few, and 
even in them there is always, as far as I have seen, a slight and 
gradual thickening or incrassation towards the extremity of those 
organs. Herri ch-ScliafFer announced, in 1843, a further distinction in 
structure between the antennae of the two Sub-Orders — viz., that their 
joints (or at least those of the middle third of the organs) were in 
the Eliopalocera twice as long as, or much longer than, thick ; but in 
the Heterocera about equal in length and thickness, or not longer 
than thick. 
The present work deals only with the South-African species of the 
first Sub-Order, viz., the Bhopalocera or Butterflies. 
