POLYDESMOIDEA.—ONISCODESMIDA, 1138 
J’. Keels otherwise formed, never exhibiting a continuous 
postero-lateral series of large setiferous teeth; keels 
of second tergal plate not larger than of the third 
(excl. Strongylosomidz) ; antennz not markedly 
clavate, when short close together. 
g. Keels of the second segment large, lower than the 
level of the first and third and projecting forwards 
beneath the angle of the first. (No indigenous 
Central-American species known.). . . . . . Fam. STRONGYLOSOMIDA. 
g. Keels of the second segment not enlarged, forming 
a continuous series with those of the succeeding 
segments and with the angle of the first. 
A. Antenne short and thick; caudal process wide, 
oblong, square or semicircular . . . Fam. PLATYRACHIDA. 
j. Margin of keels with no definite thickened } porous 
area; pores with thickened rim, not insunk, 
and situated dorsally, at a varying distance 
away from theedge . . . . . Loe Subfam. PLatyracHiIna. 
*, Margin of keels thickened, carrying the insunk 
pore, which has the margin much less noticeably 
thickened . . . . 1. ww) )).)h)0OCSubfam. Evryurina. 
kh‘. Antenne long ard slender; caudal process 
triangular, with truncate apex, or sometimes 
subeylindrical . . . 2 . Fam. CHELODESMIDA. 
k, A spiniform process projecting from the distal 
end of the second segment of the legs . . . Subfam. Xysroprsmina. 
k', No spiniform process upon the second segment 
of the legs. 
[. Phallopod with coxal calcar ; its femoral seg- 
ment without definite hair-lined depression ; 
genital processes of second leg in male blunt 
and conical . . . . . . . « . » Subfam. CHELopesMin«. 
l'. Phallopod without coxal calear ; no hair-lined 
depression on the inner side of its femoral 
segment ; genital processes of male elongate, 
stiliform . . ..... . . . . . Subfam. RusacuipEsmMina. 
Fam, ONISCODESMIDZ. 
Body strongly convex and capable of being spherically coiled, the keels vertical or nearly so, with their lateral 
margin inferior. eels of the second segment much dilated and greatly exceeding those of the other 
segments. Pores, when present, normal in number and situated on the dorsal surface of the keels. 
Instribution. Central and South America; Sumatra. 
BIOL, CENTR.-AMER., Diplop., October 1909. . Q 
