208 
Variability of Ticks 
Pattern of male scutum. 
The ornamentation consists typically of five dark-brown islands 
in a field of white-enamelled appearance, two being immediately behind 
the cervical grooves, two placed laterally, with inwardly projecting 
limbs and one in front of the festoons, containing the shallow 
dorsal furrows which determine its outline (Fig. 3); as such it is 
remarkably uniform throughout the whole series, what variation there 
is, never being sufficient to render doubtful the identification of a 
specimen. 
Fig. 3. Pvhipicephalus pulchellus, males ; ornamentation of normal form (central figure) 
and the two extreme forms, the three scuta being drawn to the same scale. N. C. del. 
The departures from the normal take place in two directions. At 
one extreme, we find that: 
1. the anterior islands tend to unite transversely; 
2. the lateral islands become triangular, with the apex of the 
triangle inwards; 
3. the posterior island forms an oval mass with its long axis 
transverse, and in a few cases (Fig. 3) actually unites with the lateral 
islands, forming a U-shaped marking, the anterior opening of which is 
partially closed by the anterior island. 
At the other extreme : 
1. the anterior islands tend to separate and are much smaller than 
in the normal scutum ; 
2. the lateral islands become free from their inwardly projecting 
limbs, which remain in the central field as two small circular patches, 
making a total of seven islands, instead of the normal number, five ; 
