530 Mr. R. I. Pocock on the Morphology and 
granular, with strongly compressed margins. Sternite gran- 
ular, its posterior border convexly rounded (fig. IIT. 18). 
Legs with several stiff setze on the lower sides of segments 
3 to 6in the anterior portion of the body ; the sete becoming 
less numerous at the posterior end; basal segment with two 
sete, second mostly with one distal seta. Third segment of 
third and fourth legs in male thickened below (fig. III. 1 d). 
?.—Very like the male, except for the presence of a 
single seta upon the lower side of the segments of the legs. 
Terga of first and second segments similarly formed. 
Number of segments 51. 
Measurements in millimetres—¢. Total length 160; 
width of first segment 12°5, of sixth (excl. tubercles) 11, of 
median 11, of penultimate segment 8. 
Loc. South India: Tinnevelly (type ¢) (C. A. Barber) ; 
Trivandrum, in Travancore (H. Ferguson). 
Eucentrobolus tamulus belongs to the same category of 
species as the form from Madras which I described as Spiro- 
bolus uroceros (Journ. Bombay Nat. Hist. Soc. vu. p. 269, 
pl. ii. fig. 7, 1892). The two, however, differ so greatly in 
the sculpturing of the terga that in the absence of inter- 
mediate types they may be regarded as generically distinct. 
For Spirobolus uroceros I propose the name Aulacobolus. 
The differential characters of the two genera are given in the 
table below. 
In the sculpturing of the terga these two genera recall 
Acanthiulus, Gervais, but differ from it essentially in the 
presence of the large and strong caudal process. 
Acanthiulus was proposed by Gervais (Ann. Sci. Nat. (8) 
i. p. 70, and Ins. Apt. iv. p. 173, 1847) for the species from 
New Guinea described by Le Guillou as Julus Blainvillei 
(Bull. Soc. Phil. Paris, 1841, p. 86). In 1893 (Ann. & Mag. 
Nat. Hist. (6) xi. p. 186) I described a second species of the 
genus, A. Murrayi, from the Aru Islands, and in the following 
year a third species was established by Daday (Term. Fiizetek, 
xvi. p. 101), under the name Spzrodolus dentatus, from New 
Guinea, without any notification on the part of the author of 
similarity between his species and Le Guillou’s. The two 
species come from the same island, and it is impossible to 
doubt that they are closely related, even if they be not 
identical. It is to be observed that Acanthiulus dentatus 
differs from the form I described as Acanthiulus Murrayi in 
the position of the pores upon the posterior elevated area of 
the terga—that is to say, behind the sulcus. In 4. Murrayi 
they are distinctly in advance of it, as in Trigoniulus. 
Nothing is said about the position of these organs in the 
