Geometridae of the Aryenline Ik])')d>lic. 207 
still almost in its infancy, I may venture on a few 
general remarks. From the extreme north I have no 
records at all, but M. Dognin has received interesting 
collections from Metan, while the neighbourhood of 
Tucuman has been a good deal worked entomologically. 
In these localities there is a considerable element of the 
subtropical fauna, though even here we realise that we 
are in a different region from the strictly equatorial, the 
gorgeous Braccinae” of Warren (Siosta, Sangalopsis, etc.) 
and many other tropical genera {Ccdlipia, most “ Pahja- 
dinaef etc.) being apparently unrepresented, others again 
(e. g. ScordyUa) quite weakly represented. On the other 
hand, there is hardly a trace (perhaps not a trace) of 
the distinctively southern, or Chilian fauna; Tephrinopsis 
siibumhrata, Dogn., may possibly be an exception from 
this generalisation. From the north-east the British 
Museum has obtained some small but valuable collections 
made about Florenzia, Ocampo and Goya; excepting, 
perhaps, Atyria chihcha (Schaus), I have not noted any¬ 
thing characteristically tropical in these, the affinities of 
the majority being distinctly with the Geometridae of 
S. Brazil and of Paraguay. When we reach Buenos 
Aires, we find nearly the same type of forms still prevail¬ 
ing; Mr. Druce has recorded Atyria durnfordi (Druce) 
from this locality, and Mr. A. F. Bayne has once taken 
Phrygionis p)aradoxata incolorata, but I am inclined to 
view these as stragglers. Mr. Bayne thinks the Rio de 
la Plata forms somewhat more of a natural boundary 
than the geographical distance would have led one to 
anticipate; at any rate he has seen at Montevideo and 
Tacuarembo several species, and even genera {Aplodes, 
Melinoides, Bronchelia, etc.), which have not yet occurred on 
the Argentine side. Of the fauna of the pampas country 
(which will certainly be but meagre) practically nothing 
is known; from its frontal armature one might hazard 
the conjecture that Hoplolygris cicatriculata (Berg) had 
its origin here, but it has spread from Tucuman and Goya 
in the north to the Rio Negro in the south. 
The very few specimens which I have seen from 
San Luis, however {Arizela didcis, Prout, Narragodes 
gyda, Prout, etc.), seem to indicate the commencement 
of the western, or Mendoza fauna. This fauna, as 
shown by my material from Balde, La Paz, and even to 
Mendoza city, and I think northward {e.g. Retamito), 
