1887]. Entomology. 283 
but on each joint, except the eight basal, there are about two 
hundred smali, hollow-curved teeth with a fine opening in front. 
In the Neuroptera (Chrysopa) there occur on the antennz, be- 
sides numerous very long tacir bristles, small pale, transparent: 
teeth. No pits could be detec 
In the Hemiptera (two ais of Pyrrhocoris only were ex- 
amined) only two kinds of tactile bristles occurred, but Hauser 
detected no pits, though Lespés states that they are present. 
Of iptera, Hauser examined more than sixty species. 
The pits in the Diptera brachycera (Muscide, etc.) are unexcep- 
tionally confined to the third antennal joint. Their number varies 
sesses two hundred of them. In flies of certain families the pits 
are compound and contain ten, twenty, and often one hundred 
olfactory hairs, partly arising from the coalescence of several pits. 
Such pits are usually divided by lateral walls into several cham- 
bers, whose connection is only indicated by their common outlet. 
Simple olfactory pits with a single olfactory style were observed 
also occur compound pits, receiving from two to ten nerve-termi- 
nations. 
The antennal pits of flies are always sac-like invaginations of 
ns 
(Fig. 2) is described at length as typical of those of brachycer- 
ous flies in general. 
The olfactory pits of the Tipulidæ seem to have a somewhat 
different structure, since the external passage is closed. It is cir- 
cular, surrounded with a slight chitinous wall and not covered 
with bristles. Such pits in their external appearance are like 
those of the locust (Caloptenus) and many Hymenoptera. They 
are situated usually on ihe third antennal joint. Pachyrhina pe 
tensis L. has about sixty of them, as have Tipula oleracea L. an 
Ctenophora. 
In the Lepidoptera, olfactory pits are much like those of flies. 
Hauser Jo in detail those of Vanessa io. Those of the 
moths were not examined, but they can be acd and satis- 
Betori. proved to be the site of the olfactory sense 
appendages dai a: of the cockroach (Periplaneta americana). I counted about 
ninety pits on eac ca stylet. They are much larger and much more numerous: than 
similar pits in antennæ of the same insect. compared them to similar pits in 
ing than hearing. in the pal . NAT., iv., Dec. 1870.) Organs of smell in the flies 
Epa aaea and in palpi, both labial and maxillary, of Perla were described in 
A. SP. 
