4 
The Non-Combed Eyed Siphonaptera 
a part in relation to plague), but on reflection we thought it would 
render the paper more useful, if we included also all the other 
Siphonaptera which have eyes but no comb on the head and pronotum. 
The scope of this paper has in consequence been considerably widened, 
but nevertheless we shall give most attention to the genus Loe¬ 
mopsylla. 
A synopsis of the genera to be discussed in 
the following pages. 
(I) Club of the antennae short, distinctly segmented only on the posterior side 
(PI. II, fig. 1, 5). Antennal groove closed behind, the genal process separating the 
antennal groove from the forecoxa (PI. II, fig. 1, 5, 13). Labial palpus consisting of 
four segments; tip of rostrum asymmetrical (PI. II, fig. 8). Hindcoxa with a comb of 
short spines on the inner side (PI. I). Fifth tarsal segment with 4 lateral bristles 
besides the subapical hair (PI. Ill, fig. 7). Antepygidial bristle separate from the 
apical edge of the seventh tergite (PI. V, fig. 5). 
The species which belong to this group are all inhabitants of the Old World, but 
Loemopsylla cheopis has become more or less cosmopolitan, as the range of its hosts 
—the domestic rats—has increased. 
We divide the species into four genera :— 
1. Mesosternite very narrow, without internal rod-like incrassation from the 
insertion of the coxa upwards.1. Genus: Pulex. 
2. Frons without tubercle ; anterior angle of genal edge produced backwards 
into a triangular lobe ; pronotum longer than metanotum (PI. II, fig. 1). 
2. Genus: Pariodontis. 
3. Frons with small mesial tubercle near the suture which separates the frons 
from the occiput; anterior angle of genal edge of head produced downwards into a 
triangular lobe; pronotum shorter than metanotum (PI. II, fig. 13). 
3. Genus: Moeopsylla. 
4. Frons without tubercle ; anterior angle of genal edge not produced into a 
triangular lobe ; mesosternite with a rod-like internal incrassation from the insertion 
of the coxa upwards (PI. I).4. Genus: Loemopsylla. 
(II) Club of antenna segmented all round, and the antennal groove open behind, 
the genal process being short (PL II, fig. 3, 12). Hindcoxa without a row of short 
spines on the inside. Labial palpus sharply segmented all round, consisting of 
4 to 7 segments, the tip of the last segment being symmetrical (PI. II, fig. 9). 
Fifth tarsal segment with 4 lateral bristles, besides a subapical hair. One ante¬ 
pygidial bristle, standing at the edge of the segment, which is sinuate (PI. VI, fig. 7). 
The species are American, with the exception of one, -which has been found far 
south on an island in the Indian Ocean and on an island off the coast of West 
Australia. 
Two genera :— 
5. Club of antenna not symmetrical, the proximal segments sloping backwards 
(PI. II, fig. 3). Genal process with only one or two bristles. 
5. Genus : Rhopalopsyllus. 
