3S>8 
The Ohio Naturalist. 
[Vol. XII, No. 1, 
lateral elevations are continuous at their base with two of the 
transverse folds in each segment and these are so produced as to 
make a distinct, zig-zag, longitudinal carina along each side of 
the body. The lateral elevations make a similar underlying 
carina less pronounced. The ventro-laterals are small, situated 
on projecting folds antero-ventral to the laterals. Ventrally in 
segments five to eleven, there are seven pairs of small rounded 
bare elevations of the integument which serve as pro-legs. 
The other appendages consist of mouth-parts, antennae and 
anterior and posterior spiracles. The mouth-parts are terminal; 
they consist (Fig. 32) of two beak-like jaws (Fig. 23, d and /), 
working vertically, and four pairs of mouth-hooks (Fig. 23, 
a and e). The upper jaw is a V-shaped chitinous piece with 
slender arms, sharply pointed at the apex; the lower one slenderer, 
more hooked, of solid chitin nearly to the base where there is a 
spur-like projection ventrally on either side. Three pairs of the 
mouth-hooks are at the sides of the jaws; slender, the bases 
embedded in the flesh for half their length, the outer one broader 
distally and with a lateral spur ventrally; the fourth pair consists 
of two triangular hooks well separated from the other parts along 
the side of the first segment. The mouth parts are all black, 
firmly chitinized and the jaws are continuous internally with 
broad chitinous plates surrounding the oesophagus (Fig. 23, b). 
Just dorsal to the mouth-parts is the pair of short antennae each 
with a basal sub-conical fleshy piece and two rounded terminal 
segments. (Figs. 21, a, and 23, c). On the anterior part of the 
third body-segment is a pair of very small spiracles (Fig. 21, b). These 
are difficult to see clearly but apparently consist of a crescent - 
shaped slit guarded by seven rounded teeth-like lobes (Fig. 24). 
The posterior respiratory organ (Fig. 21, c) consists as in other 
species of two short cylindrical appendages fused along the 
middle line and each bearing on the end three slit-like spiracles 
radiating from a dorsal circular plate. The appendage in 
Paragus bicolor (Figs. 25, 26), is slightly longer than broad, the 
length being from 0.25 mm. to 0.4 mm., the width 0.25 to 0.3 mm. 
About mid-length is a slight constriction beyond which the 
appendage is strongly chitinized and the surface smooth, tes- 
taceous brown; proximal to the constriction the surface of the 
tube is roughly papillose and nearly black. The spiracles are 
well elevated above the surface of the appendage and are 
noticeably curved in their extent. (Figs. 25 and 26, b). 
gg£ The inter-spiracular spines* are inconspicuous but the one 
median to the rather inconspicuous circular plate (Fig. 26, c ), is 
large, spoon-shaped, broad dorso-ventrally, narrower from side 
to side and concave laterally (Figs. 25 and 26, a). 
* Inter-spiracular spine, a projection of the chitinous surface between 
any two of the spiracles on the posterior respiratory organ. 
