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tip of the finger. The process of tlie clasper (PL VI. fig. 1, P) is more ronnded 

 than in faseiatuft, and its distal angle less sharp. 



The seventh abdominal sternite of the female of bnrharus varies to some 

 extent, as illustrated by PI, VI. fig. 2. As a rnle, the apical margin of this 

 segment is distinctly notched below the upper angle, this angle being sometimes 

 produced into an obtuse lobe ; but in some specimens the notch is almost 

 entirely eflPaced, the ai)ical edge of the sternite being feebly bi-emarginate with 

 the rounded upper angle slightly projecting. In fasciatus the seventh sternite 

 is never notched and its upper angle never projects. Tiie small bristles situated 

 above the stigma of the eightli tergite are more numerous in fasciatus than in 

 barbariis. 



The slightness of the distinctions between fatsciatus and baibarus suggests 

 that the two forms originally were geographical varieties of one species — i.e. 

 that barbariis was the North African race and fasciatus a European race of one 

 single sj)ecies. 



C. fasciatus, ajjart from the specimens obtained from rats, appears to us to 

 be geographically variable in Europe to some extent, as we hope to show in another 

 place. 



C. alludinis Koths. (1904), from tropical India, is another form very closely 

 allied to fasciatus. 



A large series of C. barbarus were obtained at Alger and Hammam Rirha on 

 Arcicaiithis barbarus, and also a small number of sjiecimeus at the same places on 

 Apodemus syhaticus and Mus algirus, but not one specimen on Crocidura russula. 



5. Ceratophyllus laverani Boths. (1911) (PI. VIII. fig. 0). 



C. I. Rothschild, Aim. Sti. Xut. Zuul. p. I'U'.I. toxt-fig. 1 and 2 (Iflll). 



5 ? ?, Guelt-es-Stel, o^ Eliomys quercinus, April 19, 23, and 25, 1912. 



1 S, Guelt-es-Stel, oS Met-iones skatci, April 25, 1912. 



The occurrence on Meriones is no doubt accidental. The natives brought us 

 a small number of young Eliomi/s, some tucked away in their burnouses, and 

 also many specimens of Meriones, so that it is quite possible that the larerani 

 got on to the Meriorici after the Meriones was caught. Our text-fig. 3 is taken 

 from an Algerian example. We do not notice any difference between Euroj)ean 

 specimens of laverani and these Algerian ones, which is evidence in support of 

 Mr. Oldfield Thomas's view that the specimens of Eliomtjs quercinus from the 

 High Plateaux of Algeria do not diti'er from European examples. 



6. Ceratophyllus maurus spec. nov. (PI. VII. fig. 3, 4, and 5). 



S ? . Nearest to C. kenletji Roths. (1904), from which it is easily distinguished 

 by the modified abdominal segments. Both species are characterised by one or 

 two of the apical bristles of the second hind-tarsal segment extending beyond 

 the fourth segment, the fore-femur bearing several small lateral bristles on the 

 outer surface, and the mid- and hind-coxae having less than ten bristles on the 

 inner surface (apart from the bristles placed at the anterior margin of the coxae). 

 A combination of these three characters occurs only in henleyi and maurus of 

 all the species of Ccratopln/Uus known to us. The males of maurus and henleyi, 

 moreover, bear a mane on the thorax and proximal abdominal segments. 



