PEATE CEXT. 63 
the female, and includes only a few of his former references. Upon 
the firft view of thefe opinions the point feem undetermined; and 
though we partly affent to the opinion of the laft writer, we muft 
endeavour to be entirely fatisfied, before we givea figure of Dytifcus 
Semiftriatus. 
The upper fide of this infeét is generally defcribed black; this is not 
the colour in living f{pecimens: it isof a fine gloffy 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 
ftruéture; it is nearly 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 affiftance, it can colleé& air 
bubbles, to raife itfelf from the deep parts of the water to the fur- 
face, in an inftant. The larva of the Mufca Chameleon, which lives 
in the water, colleéts the air ina bubble within the rays of its tail, 
and thereby raifes itfelf to the furface in like manner. 
Fig. 1. The eggs. Fig. 2. The larva, Fig. 3. The pupa. 
: BiACT 
