On iite G tog iitjjhical Distribution of Insects . 5?37 



Ihe south by aline parallel with SS'' S. Lat, ; on the, east b^ 

 ithe preceding region, and Buenos- Ayres ; on the west by the 

 Andes. This region is the true country of the Melasomes in 

 America, and especially of Xyctelia and the allied genera. This 

 is owing to its arid, sandy, saline soil, which presents charac- 

 ters of a more decided description in proportion as we approach 

 the Andes. After the family in question, the Carabidae are 

 most numerous. The Lepidoptera are also very niunerous, 

 but they offer nothing remarkable. 



38th, Buenos- Ayres, from the banks of the La Plata to those 

 of Rio-XegTO in Patagonia, by the 42' S. Lat., and about 200 

 leagues west of the Atlantic. We distinguish this region from 

 the preceding, on account of the peculiar characters of its soil, 

 which is in general argillaceous and covered mth grass as its 

 only produce. The insects also are in very small numbers. 

 During a long residence at Buenos- Ayres M. Lacordaire did 

 not collect, in a radius of 40 leagues round the to-^vn, more than 

 about 300 Coleoptera. The Carabidae are dominant, as in 

 Europe, and the Melasomes are restricted to a few Scotobii. 

 All the Lepidoptera met with, are a few Pieris, Colias, and Va- 

 nessa. Intertropical forms, however, are still represented here 

 by two or three beautiful species of Phanaeus, and a small 

 number of other genei'a. 



39th, Chili, with its present political limits, including the 

 Andes : although bordering on Tucuman, from which it is se- 

 parated only by the Andes, this region differs much from the 

 latter in its entomology. The Melasomes are here rather nu- 

 merous, but represented by other species. This is the native 

 country of Chiasognathus, one of the most remarkable of the 

 Coleopterous order. We here find also a few equatorial forms, 

 such as Pyrophorus, Heliconia, Castnia, &c. 



4th, Fatuqonia, from Buenos- Ayres, Tucuman, and Chili, to 

 Cape Horn ; a region altogether unexplored. Fabricius has 

 described a few Carabidse from Terra-del-Fuego ; but the en- 

 tomologists of the present day know nothing of them. 



By recapitulating these regions, it will be seen, that 14 are 

 situated in the Northern Hemisphere beyond the tropics, 19 

 between the latter, an<l 7 in the Southern Hemisphere. We 

 have overlooked a number of small i.slands scattered over the 



VOL. XXVIIl. NO. LVl. MAllCU 1840. B 



