G4 Mr. West wood on Sias^oniiim quadricorne^ SfC. 



would divide tlie family Otnalida' into two sections — the first com- 

 posed of tlic genera Oimdiuni^ Froteinus, AntJwpa^us^ Eloniuniy* 

 &c. and the second comprising Oxi/(elus, BlediuSy Eva'sthetus, Sec. 

 and then the connexion l)etween the genera appears strikingly 

 natural : Elonium, combining in itself the external appearance of 

 an Oxytelns^ and the maxillary palpi oiOmalium (to which genus it 

 bears great atTuiity, and of which, the type EL striutulum was a spe- 

 cies, both with Gravenhorst and Gyllenhall), joining the two sec- 

 tions at one point, where the insects of both sections are of an elon- 

 gate form, and the interesting genus Evccsthetus (in external ap- 

 pearance resembling the depressed Onudia, and more particularly 

 Om. letusiim (which will form a new subgenus) and which until 

 separated by Gravenhorst, was placed in the genus Oxytelus 

 and which De Jean has also placed between Oxytelus and Oma- 

 lium ;) serving to connect the two sections at the other point, 



* Staphylinus striatuhis, Fab. (Om. rugosum, Gr. Gyll.) has been formed 

 into the genus Elonium by Dr. Leach — but I believe no characters have yet 

 been published of it. 



Plate II Fig. 6 represents the Maxilla of this Insect. 



Fig. 5 ditto of the genus Omalium. 



(the type of which I consider to be Omal. rivulare) 



Fig. 7 ditto of Oxytelus cariiiatus, 



(Staph, rugosus Marsh.) which I consider as the 

 tyix" of that genus. 



Fig. 8 ditto of Siagonium quadricorne. 



Fig. 9 ditto ofZirophorus fronticornis. 



And it is not a little singular tliat these two last Insects, which, from their ap- 

 parent affinity with Oxytelus, we might infer would possess maxillary palpi 

 similar to those of that genus, present these organs nearly agreeing in form 

 with those which Omalium possesses. Indeed from my own observations on 

 the subject, I have little hesitation in saying, that the maxillary palpi alone do 

 not present characters sufficiently precise to enable us to found our divisions 

 upon them, and I am confirnud in my opinion by Mr. MacLeay's remarks, 

 both in his Ilorre Ent. Part. 1. and also in his Annulosa Javanica, and more 

 particularly in his observations in the last mentioned work on Latreille's 

 Section of Carabida; " Subulipal|)es" (Bembidium) which was established on 

 the same organ : and Mr. Kirby likewise in his Century of New Insects, (Lin. 

 Trans. Vol. 12), speaking of the comparative length of the maxillary and labial 

 palpi upon which the genus Megncephala is built, gives it as his opinion that 

 it merely indicated the section of a genus, rather than a Genus. 



