OF THE MALTESE ISLANDS. 59 
which they are attached is mounted so that a dorso-ventral aspect is presented 
under the lens of the microscope; and for this reason apparently they have been 
hitherto overlooked by all the students of this genus of insects. It is true that 
Grassi (3, p. 12) has noted that “here and there one can observe a short hair 
curved and relatively thick”; but that he failed to recognise the true character 
and arrangement of these spines is perfectly clear. Now that they have been 
discovered it is highly probable that they will be found to exist in the majority 
of species, if not in all, and may I think be considered of generic importance. 
Annandale in his description of the genus Brunettia, a new Psychodid 
discovered in Southern India, refers to a similar character, but in this instance 
the paired spines are somewhat S-shaped and relatively much stouter than the 
corresponding spines in Phlebotomus. In the light of these discoveries, therefore, 
it is possible that similar spines may be discovered in various other members of 
the same family, though it is highly improbable that such structures will 
eventually be found to exist in all of them. 
Palpi (figs. 1 and 13).—These organs are generally said to be composed of 
four segments, but there are undoubtedly five, and this number may I think be 
considered common to all the members of this genus. Annandale (1) has pointed 
out that “a minute basal joint can sometimes be distinguished in fresh specimens ” 
but that it is “ often difficult to see and appears to be imperfectly separated from 
the others.” That the small basal segment is clearly articulated to the 
second there can be no doubt, as it can be seen quite distinctly when mounted so 
that it is not obscured by the surrounding structures. All of the segments are 
clothed (in P. papatasti at least) with variously formed scales, intermixed with 
a few hairs. The scales on the first three segments are for the most part very 
long and somewhat hair-like, those on the remaining segments short and closely 
packed together. The fourth and fifth segments, especially the latter, are 
distinctly but somewhat irregularly annulated or ringed, a character which has 
also been hitherto overlooked by former investigators. In life, when these 
organs are at rest they are bent downwards and backwards at the articulation of 
the third and fourth segments, so that the anterior half of the palpus is folded 
back more or less upon the proximal half; by this curious arrangement 
practically the whole of the proboscis is covered or protected (fig. 1, pad. 1). 
Proboscis (figs. 1 and 3).—Slightly shorter than the head, inclusive of the 
clypeus ; in form it is somewhat cylindrical and slightly recurved distally. In 
the female it is composed of the following parts :— The labium (fig. 3, lb). This 
is much the largest organ, and as far as one can judge by viewing it in optical 
section, it almost completely embraces the labrum-epipharynx ; the proximal 
half is sparsely clothed with lanceolate scales, and the first third is markedly 
narrower than the rest ; immediately in front of the dark chitinous apodeme or 
sclerite is a curved row of long fine hairs ; the labella are scarcely broader than 
the widest portion in the region of the apodeme, and are clothed with a number 
of fine and rather long hairs. The labrum-epipharyne (fig. 3, lbr) is relatively 
narrow and the sides are parallel, but the apex is ‘suddenly attenuated, the tip 
bluntly pointed, and the margins furnished with a series of long spimose teeth set 
closely together and numbering about twenty on either side; ventrally it is 
