486 BRITISH OEIBATIDiE. 



if present at all, are not of the ordinary type ; they 

 are short, thick vessels, irregular in shape, and with 

 thick corrugated walls (PL D, fig. 11) ; these are de- 

 scribed in vol, i, pp. 171, 172. 



The Caeca of the ventriculus probably attain their 

 maximum size in this genus (PL E, fig. 3). They often 

 greatly exceed the size of the ventriculus itself and are 

 generally sausage-shaped. 



The Expulsory vesicles are generally well developed, 

 and mostly discharge by a pore on the dorsal surface 

 some little distance from the postero-lateral angle. 



The Ovipositor is short and thick, but not so short 

 as that of Damceus. 



The Hairs and Cuticle. — In many species {N. horri- 

 dus, N. spiniger, &c.) the large hairs arising from the 

 anterior and posterior apophyses, and also sometimes 

 the whole surface of the body, and even occasionally 

 the smaller lateral hairs and most of those on the legs, 

 are thickly set with short, blunt-ended, villous pro- 

 cesses of the cuticle (PL XLVII, fig. 12) ; these 

 processes are very easily rubbed off, and are usually 

 matted up with dirt, so that they can only be properly 

 seen in clean unrubbed specimens. 



The Nymphs of this genus usually resemble the 

 adults and would be supposed to be their immature 

 stages ; but they are of course monodactyle, and are 

 less chitinized, have the abdomen lighter in colour, and 

 what become apophyses in the adult are generally great 

 mammilliform or papil]ary lobes in the nymph. 



The Adults are very sluggish, moving extremely 

 slowly. They are very generally distributed. 



