122 



long, not well distinguished from the surrounding chitin in front and laterally and 

 mounted with a number of pointed hairs placed in transverse rows along its 

 almost straight hinder margin and limiting the sexual opening in front; a thin 

 membrane, anteriorly provided with longitudinal lines (m), is found. The opening 

 is on each side continued into a transverse groove, prolonged just in front of the 

 first pair of the stigmata. The posterior plate is both longer and broader than 

 the anterior (fig. 7 b, p), distinctly broader than long and with a row of about five 

 pointed hairs on each side from the side to near the middle; there is no trace of 

 marginal membrane but just behind the margin in tlie middle an area, mounted 

 with a number of minute pointed granules (sp'); club-shaped accessory glands like 

 those of Ch. granulatus C. K. are found in great number (gl). The area of Cb. 

 Murrayi Poc. is almost completely like the one described, but the granulation 

 behind the opening is wanting and a pair of short rounded bodies on each side 

 beneath the posterior plate, and perhaps corresponding to the ram's-horn-shaped 

 organs of Ch. granulatus C. K., is found. 



2. Ch. granulatus C. K. (PI. Ill, fig. If). Croneberg has pp. 456—57 given a 

 very good description of the genital apparatus of this species, accompanied by a 

 number of figures (45. taf. XI a, figs. 44-47). The genital area consists of two plates, 

 an anterior (a) and a posterior (p), between which the transverse sexual opening is 

 placed; the anterior plate is really cup-shaped with the cavity of the cup facing 

 towards the posterior and including a portion of the inner organs; it is only partly 

 visible from below, while its anterior thinly-skinned surface is very well developed. 

 The ventral side of the anterior plate is longest in the middle and here continued 

 into a fairly prominent and rounded tubercle densely crowded with pointed hairs; 

 the hinder margin of the anterior plate is laterallj* distinctly concave and in the 

 middle convex, but with a slight curvature forwards; the posterior portion of this 

 |)late is limited ofl" from the remaining part by a transverse line, has a laterally 

 well defined marginal membrane and a marginal row of pointed well articulated 

 hairs, which in the middle are placed in more than one transverse row and are 

 bifurcate (fig. 1 f ). The posterior plate is much longer and broader than the anterior, 

 and distinctly broader than long; it shows, when observed from below, a median 

 longitudinal depression, sloping towards the front margin, with an anterior elevation 

 on each side, corresponding to the hollows, in which the ram's-horn-shaped bodies 

 are placed (fig. 1 f, p and r). The anterior margin is distinctly concave in the 

 middle corresponding to the median depression, and on each side of this concavity 

 distinctlj' convex opposite to the concavities of the posterior margin of the other 

 plate. Laterally no marginal membrane is found but a fairly long one at the 

 bottom of the median concavity. If we examine the posterior plate from the upper 

 or inner side, we will in the middle find a kind of gutter, built up by a compli- 

 cated chitinous apparatus, which emits the discharge of a mass of club-shaped 

 glands (45. fig. 45, cir; and pi. Ill, fig. 1, /"), near the concave anterior margin; on 

 each side in the middle near to the front margin four dentated hairs are found 



