480 EXTERNAL ANATOMY OF INSECTS. 
a distinct name and notice, which IT conceive in some 
sort to be analogous to the nostrils of quadrupeds, and 
which I have therefore named the Rhinarium or nostril- 
piece. I had originally distinguished it by the plural 
term zares, nostrils; but as it is usually a single piece, 
I thought it best to denote it by one in the singular. 
When I treat of the senses of insects, I shall give you 
my reasons, as I have before said, for considering this 
part as the organ of scent, or connected with it, which 
you will then be able to appreciate. I shall only here ob- 
serve, that the piece in question is in the usual situation 
of the nostrils—between the nose and the lip. In a large 
number of insects this part may be regarded as nearly 
obsolete ; or at least it is merely represented by the very 
narrow and membranous line that intervenes between 
the nose and the lip and connects them; which, as in 
the case of the head of some Harpalide before noticed, 
may be capable of tension and relaxation, and so pre- 
sent a greater surface to the action of the atmosphere. 
But I offer this as mere conjecture. In the lady-bird 
(Coccinella) this line is a little wider, and becomes a di- 
stinct rhinarium ; as it does also in Geotrupes. With 
respect to its zmsertion, the rhinarium is a piece that 
either entirely separates the nose from the lip, or only 
partially: the former is the most common. structure. 
It is particularly remarkable in a New Holland genus of 
chafers (Anoplognathus). In A. viridieneus it is very 
ample, and forms the under-side of the recurved nose, 
so that a large space intervenes between the margin of 
the latter and the base of the labrum. In Acrocinus of 
the Capricorn tribe, the nostril-piece, which forms a di- 
stinct segment, is narrower than the nose, and the up- 
