398 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 underh'ing 

 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-Hke 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 chitinizcd and the jaws arc 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 rotmded tenninal 

 segments. (Figs. 21, a, and 23, c). On the anterior part of the 

 third body-segment is a pair of very small spiracles (Fig. 2 1 , ^) . 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 2(5, b). 



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. 



