74 DIPLOPODA. 
SPIROBOLUS, Brandt. 
Spirobolus, Brandt (in part.). 
Spirobolus (s. s.), Pocock, Journ. Linn. Soc., Zool. xxiv. p. 484 (1893). 
Type, Spirobolus bungii, Brandt (from China), 
For characters of this genus, see ¢nfrda. 
Apart from sexual features, the differentiating characters of the 
species of this genus known to me may be tabulated as follows :— 
a. Eyes large, each consisting of about 60 ocelli; interocular area only a 
little greater than the diameter of each cluster of ocelli . . . 
a’. Eyes smaller, the ocelli less well defined and only about 20 in number 
on each side; interocular area from three to four times the diameter 
of each group of ocelli. 
b. Infero-lateral crests exceedingly strong and widely spaced even quite 
at the posterior end of the body, each crest projecting as a spiniform 
process beyond the edge of the tergal plates ; sternal plate of anal 
segment acutely angular posteriorly . 
_ b'. Infero-lateral crests weaker, more numerous, not projecting as strong 
spiniform processes, although sometimes forming a series of serrations ; 
sternal plate of anal segment rounded or obtusely angled posteriorly. 
c. Infero-lateral angles of the second and third tergal plates rectangular, 
that of the third not like that of the fourth, which is widely 
rounded . . 
. Infero-lateral angles of the third tergal plate evenly rounded like 
the fourth, that of the second usually widely convex. 
d. A second anterior transverse sulcus extending across the tergal 
plates from pore to pore in front of the normal sulcus. 
e. Lateral portion of first tergal plate not widely emarginate 
inferiorly infront . . 2. 1. 2 6 2 ee ew ee . 
. Lateral portion of first tergal plate widely emarginate inferiorly 
in front. 
f. Normal transverse sulcus complete and stronger, at least 
laterally, than the secondary sulcus in front of it; legs 
yellow . 2 6 we we ee ee ee ee, 
f'. Normal transverse sulcus weaker than the secondary sulcus 
in front of it on all the segments, sometimes almost 
obsolete; legs fuscous a 
d'. No secondary transverse sulcus on the tergal plates in front of 
the normal transverse sulcus, which may be almost obsolete. 
g. Median and posterior portions of dorsal area of terga almost 
smooth, polished, not perceptibly punctured or longitudinally 
striolate; posterior inferior angle of second tergal plate rounded 
but rectangular, the posterior and inferior edges almost at right 
angles to each other . 
Central-American 
platyops, sp. i. 
hoplomerus, sp. n. 
stolli, sp. n. 
tepanecus, Sauss. 
mystecus, Sauss. 
monticola, sp. 0. 
godmani, sp. 0. 
