Genera uiul Specits of (^olco'^taY'd. 39 



of India, that it would be premature to speculate as to its cha- 

 racter ; but although in its animal productions there is a i-emark- 

 able amount of Northern temperate forms, they could never have 

 been expected to predominate to such an extent in any one group, 

 as it now appears they do, judging, however, solely from the facts 

 here stated*. There is one point in connexion with this subject 

 which can only be just alluded to here, viz. the apparent tendency of 

 animals to migrate to the south, and not the reverse, or very slightly 

 sof. The idea fii'st occiuTcd to me in noticing the very few Austra- 

 lian forms of Coleoptera occurring in Mr. Wallace's Indian Island 

 collections contrasted with the number of these Indian forms in 

 Australia, especially its northern parts ; — compare also Natal with 

 the Cape, or the United States with Mexico or Cuba ; notice Upper 

 Egypt, Arabia, Persia, <fec., just receiving a tropical form here and 

 there, 



Gasnonia [Carabidae]. 



LatreiUe, Icon, de Coleop. d'Europe, ed. 1. p. 77. 



Casnonia alleaa. 



C. picea ; capite intra ocidos profunda limato-impresso ; prothorace 

 capite breviore, postice transverse corrugate; elytris leviter striatis, 

 singulo macula flavescenti apicem versus ornato. 



Hab. Australia (Moreton Bay). 



Pitchy, shining ; head rather broad, a deep semicircidar impression 

 between the eyes and the epistome ; prothorax not so long as the head, 

 somewhat elliptical, smooth anteriorly, but with delicate transverse 

 folds behind ; elytra about the length of the head and thorax together, 

 and three times the width of the latter at its base, faintly striated with 

 an oblong yellowish patch towards the apex of each ; antennae dark 

 brown ; legs pitchy, femora at the base and tibiae in the middle (nearly 

 obsolete, however, in the anterior pair) testaceous-yellow ; body beneath 

 pitchy-brown, shining. Length 5 lines. 



Although the genus Casnonia is found in India as well as in 

 South America, this is, I believe, the only species yet detected in 



* While this sheet was passing through the press, Dr. Adams received another 

 collection from Dacca, evidently made in a more favoiu-able season ; still, although 

 there is an addition of many tropical genera, Eui-opean vastly predominate ; and 

 it is worth notice, that nearly all these tropical genera have a very wide range, as 

 for example, Anfhia, Chrysochroa, Prot(Btia,Xyloni/chus,Cerosferna,Olcnocampti(s, 

 Glenea, Apomccyna, Batocera, Xylorhiza, &c., all of which are represented by the 

 commonest species. 



t The same tendency has been noticed in plants, so far as those of America 

 and Australia are concerned. 



