NEW GENERA AND SPECIES OF BRACHELYTIIA. 189 



it in those works to which I have access, or by the friends to 

 whom I have referred, I am advised to adopt the present mode 

 of pubhshing a description of it. 



Of this genus four species are clearly distinct, as will subse- 

 quently appear; and two more, I apprehend, are sufficiently 

 so to warrant their separation, but from their rarity it is diffi- 

 cult at present to speak with certainty respecting them. Their 

 locality, with one exception, which will be immediately noticed, 

 is in damp decaying vegetable matter ; they are very lively and 

 active, in many points closely resembling each other; they are 

 all clothed with a short sericeous pubescence, which in the 

 living insect is very brilliant. In all of them there is an iso- 

 lated seta placed near the middle of the intermediate tibiae : 

 in colour they are so much alike, that it becomes a difficult 

 task clearly to point out their distinctions by descriptions. 

 The locality of one species (C elongatd) before alluded to, 

 differs from its congenera ; the only spot in which I have met 

 with it being a bank of clay on the edge of a stagnant pool, 

 where it burrows like the Heteroceri, and can rarely be seen on 

 the surface. 



The other genus, which I have called Deinopsls, is nearly 

 allied to the foregoing. Its habits, its locality, the rapidity of 

 its motions, and the pubescence with which it is clothed, are 

 precisely similar ; indeed its whole appearance bears the 

 strongest resemblance to them ; but when the separated parts, 

 especially those of the head, are examined, a difference so 

 great is immediately seen as to make a separation unavoidable. 

 Of this genus I have met with only one species. The follow- 

 ing valuable observations, accompanied by the dissections given 

 in the cuts, were sent me by my friend Mr. Westwood, for 

 which I beg to offer him my best thanks. 



" In Ceiitroglossa the mandibles, which are acute, are slightly 

 hooked at the tips, and without any teeth on the inner margin, 

 being only slightly serrated below the middle, are furnished 

 on the inside with a large flat transparent appendage, thick- 

 ened along the centre, with the inner margin straight, and 

 discovered, under a very high-power lens, to be exceedingly 

 finely serrated ; the back of this, at the tip, is rounded, the 

 opposite angle being acute. In some of the Brachelytra we 

 find a minute appendage attached to the inner edge of the 

 mandible, of which this is evidently the analogue ; but in this 



