CHAMBERLIN: THE CHILOPODA OF BRAZIL. 171 
Branchiotrema Kohlrausch, Journ. Mus. Godef., 1878, p. 70; Archiv. naturg., 
aea8,.47;,1, .p. 70. 
Parotostigma Pocock, Biol. Centr. Amer. Chilopoda, 1895, p. 25. 
Of this genus nine species are at present known from Brazil, five 
of these being here described as new. 
Key to Species. 
a. Tarsal spines wholly absent or, rarely, a few of the legs with a 
men reduced spine................-4-- O. liambatus (Meinert). 
aa. ‘Tarsal spines present and distinct. 
b. Dorsal plates of caudal half of body distinctly scabrous, 
bearing rows of fine elevated spinous points. 
e. Last ventral plate without distinct median sulcus; only 
the two proximal articles of the antennae glabrous; with 
five rather small keels or keel-like elevated lines on dorsal 
plates of caudal portion of the body...O. casus, sp. nov. 
ec. Last ventral plate with a distinct median longitudinal 
sulcus; two and a fourth or two and a half proximal 
articles of antennae glabrous; only a single, flat, median 
keel present on dorsal plates. 
d. Twentieth legs without a tarsal spine; only one tooth 
on each dental plate distinct, the others being com- 
pletely fused; head and first dorsal plate abruptly 
different in color from the other plates, brownish. 
O. rex, sp. nov. 
dd. Twentieth legs with a tarsal spine; each dental plate 
with four distinct teeth; head and first dorsal plate 
not abruptly different in color from the other plates, 
olivaceous..... O. scabricaudus Humbert et Saussure. 
bb. All dorsal plates smooth, those of the caudal half of the body 
not distinctly scabrous. 
ec. First eighteen or nineteen pairs of legs with two tarsal 
spines. 
d. First eighteen pairs of legs with two tarsal spines; 
twentieth legs with a tarsal spine; dorsal plates with 
a conspicuously elevated double keel each side of 
middle, the dorsal sulcus of each side lying between 
the halves of this keel.......... QO. tidius, sp. nov. 
