44 
The Non-Combed Eyed Siphonaptera 
Modified segments. </. The eighth sternite (PI. IV, fig. 8) bears 
4 or 5 long bristles along the ventral edge, the last two being the 
longest; besides these there are a number of bristles on the side as 
shown in the figure. The manubrium (M) of the clasper is longer than 
the distance from its base to the top of the longer process of the clasper. 
There are two free processes to the clasper, the upper one being- 
somewhat broad and asymmetrical, its upper margin being rounded, and 
the lower margin somewhat incurved, the bristles situated at and near 
the apex and upper margin being long. This process is very distinct 
from that of every other species known to us. The ninth sternite (ix. st.) 
almost gradually widens from the base to the apex, the upper margin 
being nearly straight and the ventral margin bearing a number of small 
hairs from near the base to the apex. The internal plate of the penis 
is somewhat curved upwards at the end, the ventral margin being- 
rounded and the upper corner pointed.— $. The eighth tergite (PI. VI, 
fig. 1) bears externally along the apical edge a row of 12 to 16 (usually 
13) bristles, and a row of 8 or 9, rarely 10, shorter ones inside, on the 
outer surface there being an irregular row of usually 8 to 10 bristles 
which are placed between the lateral and apical rows. The stylet is 
short, bearing, besides the long apical bristle, one or two short ones 
situated on the outer surface. 
Length. 14—1*7 mm., $ 2T—2 - 7 mm. 
This species appears to occur in all warm climates, being distributed 
by rats. It is presumably the means of the transmission of the bubonic 
plague from rat to man. The true home of this flea appears to be the 
Nile Valley, where it occurs commonly on various hosts. 
Though we have not seen the specimens which were named 
brasiliensis and philippinensis (see bibliography, above), we have little 
doubt that the names refer to the present insect. 
L. cheopis formerly was generally referred to as Pulex pallidus 
Tasch. in the literature on bubonic plague. 
In most of the $ $ off Gerbillus and Jaculus as well as in the single 
one we have off Lepus rothschildi, the hindcoxa is broader than is the 
case in typical cheopis. The first midtarsal segment, moreover, is longer 
and the tooth of the hindfemur larger. These specimens are possibly 
the $ $ of the two mentioned under L. nubicus. 
We have L. cheopis from the following localities and hosts: 
Shendi, Egyptian Sudan, off A comys witherbyi, Arvicanthis testi- 
cularis, Dipodillus wcitersi and Genetta dongolana. 
Meroe, Dongola, off Arvicanthis testicidaris. 
