(371 ) 



The upper spine of the genal comb (PI. XII. fig. 18) covers the genal process 

 to a greater extent than in L. aethiopicus. The pronotal comb contains twenty-two 

 spines on the two sides together, besides a small ventral spine on each side. The 

 jiroportional lengths of the first and second segments of the tarsi are appreciably 

 difl^erent in L. aethiopicus and L. algira, the first segment being longer in the 

 former species than in the latter. The measurements of the mid- and hind-tarsi are 

 in L. algira : 



Mid-tarsus: S, 18, 15, 11, 8, 14 ; ?, 17, 13, 10, 7, 13. 



Hind-tarsus : c?, 39, 24, 16, 9, 15 ; ? , 37, 21, 15, 8, 14. 



Modified Segments. — S. The movable process (PI. XII. fig. 17, F) reaches to the 

 apex of the clasper in the species mentioned above as well as in the new one, and 

 is more or less convex on the distal side and concave on the proximal side, being 

 of almost even width in taschenbergi with the apical portion slightly tapering 

 (according to Wagner's figure), whereas it is broadest beyond the centre in algira, 

 and almost club-shaped in aethiopicus. It bears five bristles on the distal side, of 

 which the last but one is the longest, the last the second longest, and the other 

 three are thin and nearly equal in length. The clasper is produced into a long 

 process (P), which is slightly curved towards the " finger " (F) and somewhat 

 widened before the apex. This process bears a long bristle at the distal margin 

 beyond two-thirds of the way from the insertion of the finger to the ajiex of the 

 process, a small bristle being placed farther apically and a minute hair on the dorsal 

 side. The manubrium (M) is shorter than the clasper in algira, while it is longer than 

 the clasper in aethiopicus as well as in taschenbergi. The distal portion of the ninth 

 sternite is very complicated both in algira and aethiopicus (and presumably also 

 in taschenbergi) and only differs in the detail in the two species, this sternite in 

 algira bearing fewer bristles and being broader at the apex. The eighth sternite 

 (PI. XII. fig. 17, viii. St.) is triangular in a lateral view in algira and has five bristles, 

 whereas in aethiopicus it is conical with the tip rounded and bears a larger number 

 of bristles at and near the apex. 



? . This sex is at once distinguished from the ? of aethiopicus by the seventh 

 sternite (PI. XII. fig. 19, vii. st.) being divided by a deep sinus into a narrow and 

 pointed upper lobe and a broader and longer lower one. The bristles on the eighth 

 tergite are fewer in number in algira than in aethiopicus, the former bearing about 

 a dozen bristles on the widened ventral portion of the segment, while aethiopicus 

 has sixteen or more. The stylet is somewhat longer in algira than in aethio- 

 picus, the head of the receptaculum seminis (PI. XII. fig. 19, r.s.) being also longer 

 and narrower than in aethiopicus. 



The antepygiJial bristles of algira and aethiopicui (and perhaps taschenbergi) 

 are remarkable for their arrangement. The c? bears on each side three and the 

 ? four, and these bristles are divided into two sets separated by a sinus of the 

 hind-margin of the seventh tergite, there being two bristles above the sinus and 

 one below it in the i, and two above and two below it in the ?. In L. muscidi, 

 sobrinus, pectiniceps, etc., the sockets of the antejjygidial bristles of each side are 

 contiguous, there being no interspace within the cluster. 



L. algira was plentiful on Arvicanthi.s barbarus at Alger and Hammam Rirha 

 together with Ceratoplujllus barbarus, both fleas being found on the same indi- 

 viduals of the host as well as in the nest. We also found a few specimens on 

 Crocidura russula and Apodemus sijlvaticus, which are doubtless accidental 

 hosts. 



