SPECIES OF CEYLON PEDIPALPT. 139 
Length.—Up to three and. a half millimetres. 
This species is very closely allied to S. (7'.) modestus, Hansen, 
from New Guinea and New Britain. It differs chiefly in having the 
anterior angle of the trochanter of the arms rounded and the 
anterior margin convex ; in having the foot of the antenniform legs 
proportionally shorter and stouter; and in the greater stoutness 
of the tail, which is, moreover, always somewhat swollen at about 
the middle of its length. 
The colour of 8. (7'.) vittatus is very constant even in young speci- 
mens, and quite distinct from that of S. (7’.) medestus, resembling 
rather that of another allied species, S. (7'.) procerus, Hansen, from 
Singapore. The sharply defined white and green segmental bands 
of the abdomen are always present, and are distinctly visible to the 
naked eye. 
Sections show that the specimens here described include without 
doubt many mature females. 
The chief interest of these two new species lies in the abundance 
in which they were obtained. Hansen had but a few specimens of 
each of the species he described, and can have had little direct evidence 
as to which points were likely to be constant and which were not. ° 
He found the proportions of different parts of the antenniform legs 
to be among the most useful characters by which to distinguish 
the species; especially in the female sex; and the value of this 
selection is confirmed by the fact that in each of the long series of 
Schizomus (s. str.) crassicaudatus, S. (Trithyreus) peradeniyensis, 
and S. (7'.) vittatus which I have examined these characters remain 
perfectly constant. Only in one instance have I noticed any 
abnormality, and as this occurred on one side of the specimen only, 
and affected the number of joints in the foot, it was presumably 
a malformation caused by some accident to the appendage in 
question. 
The form of the lower anterior portion of the trochanter of the 
arm is another useful character ; but this is less fixed, and should not be 
relied upon unless a good series of specimens are available. Thus, 
Hansen states that in Schizomus (s. str.) crassicaudatus “‘ the best 
distinguishing mark between this species and all other forms 
hitherto known is the presence of a process from the lower 
front angle of the trochanter of the palps”’; this process, as they 
point out, is smaller in the female than in the male, and in the 
former I find it to be extremely variable in size, often minute, and 
sometimes entirely absent. The distinctive proportions of the parts 
of the foot of the antenniform legs being constant are of much 
greater systematic value, and it may not be out of place here to 
reiterate Hansen’s emphatic statement that “ measurement by the 
eye of such parts is quite insufficient”; the use of an eye-piece 
micrometer is absolutely necessary. 
