Systematics of certain Chilognathous Diplopods, 531 
description of Blainvillei, the type of Acanthiulus; but 
the similarity in other particulars between dentatus and 
Blainvillei justifies the conclusion that in the latter form also 
they occupy the abnormal backward position described and 
figured by Daday in his species. In that case Murrayi 
cannot, strictly speaking, fall into the genus Acanthiulus, 
but must stand apart as the type of another genus, for which 
the name Polybunobolus is proposed. P. Murrayi further 
differs from dentatus and Blainvillet in the much greater 
length of the antenne. This, however, may be a character 
only of specific value. 
The four Oriental genera under discussion may be 
distinguished as follows :— 
a. Anal segment armed with a long, stout, 
apically pointed caudal process. 
a. Posterior area of terga not longitudinally 
erooved, but furnished with a row of 
larger and smaller tubercles irregular in 
BI ZeTAMC SPACING, Wer gie's wsteyaecieitem oka EUCENTROBOLUS, noy. 
61. Posterior area of terga longitudinally 
grooved and furnished with a series of 
low tubercles equal in size and evenly 
spaced, situated upon the areas between 
HERETO OWES mre ettet petra siy os ictlevele: vip «sales AULACOBOLUS, nov. 
b. Anal segment not produced into a caudal 
process surpassing the valves. 
a>, Pores in front of the sulcus on the median 
area of the terga; antennz even in the 
female much longer than face ........ POLYBUNOBOLUS, nov. 
6?. Pores behind the sulcus on the posterior 
elevated area of the terga; antenne 
short, even in male not longer than face. AcANTHIULUS, Gerv, 
CoLOBOGNATHA. 
? Genus SrpHonortus, Brandt. 
Siphonotus brevicornis, sp. n. 
? .—Colour yellow, with two conspicuous fuscous patches 
on each segment, forming a pair of fuscous bands extending 
from the first to the last tergal plate, the patches larger and 
closer together on the anterior than on the posterior terga ; 
hence the median yellow band that separates them is wider 
posteriorly than anteriorly. 
Head piriform, longitudinally grooved above, hairy below. 
Antenne very short and thick, not longer than head, all 
the segments much wider than long, 
Terga finely rugose, with faint longitudinal strie; pleurz 
coriaceous. 
