278 MR. J. O. WESTWOOD ON NYCTERIBIA. 
In all the three individuals under examination, on each side of the head, near the 
anterior angles, an eye is placed, composed of two small raised black tubercles. 
Latreille describes these organs in his Nyct. Blainvillii as possessing a somewhat si- 
milar construction, being “‘ noir et composé de petits grains réunis ;” but Mr. Curtis 
characterizes the genus with “‘ eyes and ocelli none?”; and M. Dufour, in his descrip- 
tion of the species which he names Nyct. Vespertilionis, seems to consider Latreille’s 
account erroneous, stating that the eye in that species is ‘‘d’un blanc grisatre, trés- 
lisse et parfaitement simple.’’ We shall subsequently see, from the description of my 
Chinese species, that both Latreille and M. Dufour are correct. 
Fabricius, Hermann, and Mr. Curtis characterize the genus as being destitute of 
antenne; and M. Dufour states that ‘‘les investigations les plus scrupuleusement 
réitérées ne m’ont pas fait découvrir le moindre vestige d’antennes” in his Nyct. Vesper- 
tilionis. Latreille, however, describes his Nyct. Blainvillii as being furnished with two 
antenne, inserted in the superior emargination of the front of the head, very short, 
contiguous, advancing parallelly, and two-jointed, the last joint being the largest, and 
subtriangular, but rounded externally. M. Dufour therefore considers, without much 
regard to the weight of analogy, that these organs are exclusive to Nyct. Blainvillii. In 
the species under examination they exist precisely in the form described by Latreille, 
which I need not repeat ; as well as in all the individuals of other species which I have 
been able satisfactorily to examine. As these organs are flat and closely applied together 
at the interior margin, we may probably not be far from correct in considering that 
M. Dufour has overlooked them as distinct organs, regarding them as the produced 
front of the head. 
The structure of the mouth next demands our attention. The description of it given 
by Fabricius is very inaccurate, since he describes it ‘‘ os parum prominens—vagina 
bivalvi—valvulis obtusiusculis—palpi triarticulati,” &c. With the exception of the two 
large external organs, which they have considered as palpi, Latreille and M. Dufour 
were unable to ascertain the structure of the oral apparatus; and the figure given by 
Mr. Curtis of the head does not convey an adequate idea of its organization. 
At the lateral anterior margins of the head, and extending beneath a short distance 
into its inferior emargination, are attached a pair of elongated crustaceous organs, 
strongly setose, which are advanced in front of the head, with their extremities some- 
what dilated and brought into contact, serving, in fact, as a lateral defence of the 
antenne. ‘Their interior surface is smooth ; but the external sete vary considerably in 
length, some of them being as long as the organ itself, and having a divergent direction. 
As to the nature of these organs I may observe, that having discovered the existence of 
distinct antenne, 1 am not compelled to enter with M. Dufour into those philosophical 
speculations as to the gradual degradation and transposition of the functions of various 
organs which originated in the supposed want of antenna, and the employment of the sup- 
posed palpi as such. By Mr. Curtis they are doubtingly considered as mawille ; which 
