PLATE CLXI. 63 



the female, and includes only a few of his former references. Upon 

 the firft view of thcfe opinions the point feems undetermined ; and 

 though we partly alTent to the opinion of the laft writer, we mufl: 

 endeavour to be entirely fatisfied, before we give a figure of Dytifcus 

 Semiftriatus. 



The upper fide of this infeft is generally defcribed black ; this is not 

 the colour in living fpecimens : it is of a fine glolTy black-green, and 

 the marginal colour brighter than in thofe that have been dead fome 

 time. The greenifh hue on the back feldom entirely difappears. 



The fore feet of this beetle have an appendage of a very fingular 

 ftru6ture ; it is iiearly round, flat beneath, and has in the middle two 

 remarkable circular cavities, with many others more minute : it is 

 fuppofed, that through minute apertures in thefe cavities it can emit 

 a kind of oily fluid ; or that, by their afliftance, it can colle£l air 

 bubbles, to raife itfelf from the deep parts of the water to the fur- 

 face, in an inftant. The larva of the Mufca Cham^lion, which lives 

 in the water, colledls the air in a bubble within the rays of its tail, 

 and thereby raifes itfelf to the furface in like manner. 



Fig. I. The eggs. Fig. 2. The larva. Fig. 3. The pupa. 



G 4 • PLATE 



