Genera and Species of Millipedes. 439 
less from the edge. Caudal process with two pairs of promi- 
nent tubercles at the sides of the posterior border, which is 
rather strongly though not angularly produced mesially. 
Sternal spines strong, the posterior pair directed poste- 
riorly, the anterior pair downwards and forwards. 
Measurements in millimetres.—Total length 76; width of 
second tergite 10, of fifth 12°5. 
Loc. Singapore (H. N. Ridley). 
In colouring this species seems to resemble P. subvittatus, 
Peters (Mon. Ak. Wiss. Berlin, 1864, p. 545), the type of 
the genus, which came from the island of Linga, 100 miles 
to the south-east of Singapore. ‘There is nothing, in fact, in 
Peters’s diagnosis to separate the two; but Mr. O. F. Cook, 
who has examined the type, says in his diagnosis of the 
genus Phractodesmus, “ first segment broadest at or behind 
the middle,” which is certainly not the case in Ridley? ; and 
again, “ carinz laterally margined outside the pore.”” But in 
Ridleyi the margination is scarcely, if at all, more noticeable 
than what is presented, for example, by Acanthodesmus 
Andersonit, Poc. So that, apart from geographical reasons, 
there is little doubt that the two are specifically different, 
though I strongly suspect they are referable to the same 
genus. 
Genus ILopEsMus, Cook. 
Llodesmus, Cook, Brandtia, i. p. 1 (1896), 
Ilodesmus Whiteheadi, sp.n. (Fig. 15.) 
2? .—Colour black, with a longitudinal yellow band 3-4 
millim. wide, extending from the summit of the head on to 
the caudal process; legs and antenne fulvo-fuscous ; sterna 
brown. 
Antenne a little longer than the width of the first tergite, 
much less than that of the second. 
‘irst tergite widest across the middle, its anterior border 
convex. Dorsum convex, rather coarsely but not very closely 
granular, nineteenth segment nearly if not quite smooth ; the 
rows of tubercles traceable on all the segments except on the 
first, which seems to be uniformly granular. Anterior and 
posterior borders of the keels finely serrulate, lateral border 
not emarginate, but furnished with small rounded or sharp 
teeth, irregular both in shape and number ; anterior border 
with basal shoulder ; anterior angle squared even on the fifth 
segment, often a little produced laterally, the anterior border 
straight or slightly convex; posterior border slightly concave 
