32 G. 0. Sårs. 



sent author in the 22nd volume of this Journal, to which 

 therefore the reader is referred. 



Occurrence. — This form is up to the present only known 

 from the neighbourhood of Sâo Paulo, where, however, it 

 must be very common, to judge from the abundance of speci- 

 mens raised from the small quantity of dried material received 

 from this place. 



Gen. Macrotlirix, Baird. 

 Remarks. — This genus seems to comprise a very 

 great number of species distributed in all parts of the world; 

 but in most cases the descriptions given are rather unsatis- 

 factory. Indeed, the examination of preserved specimens is 

 always connected with great difficulties, owing to the injuri- 

 ous action of the alcohol, which causes the shrinking of both 

 the body and its appendages, thus concealing the characteris- 

 tic features of the species. An examination of fresh specimens 

 is therefore required to make out the specific characters 

 sufficiently. I have myself examined about 10 different 

 species, all of which have been observed in the living state. 

 Of these 2 belong to the Brazilian fauna and will be de- 

 scribed below. I addition to these, no less than 7 species 

 have been recorded from South America by other authors, 

 2 of them having been identified with European species, 

 a 3rd with an African species, while the 4 remaining 

 species are regarded as new to science. None of the latter 

 agree with the 2 new Brazilian species here described. 



