276 MR. J. O. WESTWOOD ON NYCTERIBIA. 
Aptérologique’, regarded it (under the name of Phthiridium') as one of the Aptera, 
and Dr. Leach, in the ‘Supplement to the Encyclopedia Britannica,’ formed for its 
reception a distinct order, Notostomata, in the class Arachnides,—Latreille, with that re- 
markable sagacity which he so constantly displayed, placed it in the order Diptera, next 
to Hippobosca, with the remark, ‘‘ on croiroit que c’est une araignée a six pattes.” 
Hence Mr. MacLeay regarded it as occupying the osculant situation betwen the classes 
Arachnida and Haustellata. 
But the genus Nycteribia is worthy of the attention of the naturalist on account of 
another peculiarity. To say that the insects of which it is composed are parasitic upon 
certain Vertebrata, would be insufficient to distinguish it from numerous other para- 
sites ; but when it is stated that this genus is exclusively confined to that equally ano- 
malous group—Quadrupeds we can scarcely call them—the Chiroptera, the evident in- 
tention of Nature in preserving the system of osculant divisions cannot be overlooked. 
Many of the singular peculiarities of structure of this genus have been ascertained and 
described by some of the most celebrated entomologists, and the memoir of Hermann 
above noticed, that of Dr. Leach inserted in the ‘ Zoological Miscellany’?, the article 
Nycteribie by Latreille in the ‘ Nouveau Dictionnaire d’Histoire Naturelle’, the memoir 
by M. Leon Dufour upon this genus published in the ‘ Annales des Sciences Naturelles’ 
for April 1831, and the figure and description of Nyct. Latreidli contained in Mr. Cur- 
tis’s ‘ British Entomology’‘, are especially to be referred to. 
Still, however, some of the most important characters of these insects remain involved 
in uncertainty, either from the silence of authors respecting them, or from the inaccu- 
rate or insufficient manner in which they have been described: among which are to 
be noticed the nature of the transformations which they undergo; the distinction of 
the sexes, and consequently the sexual characters and the different organization of the 
abdomen in the sexes ; the structure of the mouth, antenne, and eyes ; the separation of 
the metasternum and abdomen; the situation and construction of the spiracles ; and the 
nature of the serrated organs between the base of the anterior and intermediate legs : 
upon all which points I hope to be able to offer to the entomologist satisfactory details. 
For the materials enabling me to do this, I have to express my obligations to Lieut.- 
Colonel W. H. Sykes, who has kindly permitted me to examine three female specimens 
of the largest species of the genus, brought home by himself from the East Indies, and 
preserved in spirit; to the Rev. F. W. Hope, for permission to examine two male 
specimens of a large species from Bengal; to the Rev. Leonard Jenyns, who has pre- 
sented me with a male of a very distinct and moderate-sized species from China pre- 
' Published in 1804. Latreille had previously established the genus under the name of Nycteribia in his 
«Précis des Caractéres Génériques’, }795, and in his ‘Histoire Naturelle des Insectes et des Crustacés’, tom. iii. 
An X. (1802). 
2 Vol. iii. + Nouv. Edition, 1818. * Plate 277. 
