GENUS NOTHRUS. 483 



spiniger is also a good example) ; the terminal joints 

 are also often somewhat geniculate, and abundantly 

 furnished with hairs (PI. XL VI, fig. 3). 



The Maxillae are generally long and projecting, and 

 usually sharply and deeply dentate (PI. XLY, fig. 6 ; 

 see also N. spiniger'^ where each maxilla has four teeth 

 of the same character). 



The Mandibles are short and broad, small in pro- 

 portion to the size of the creatures ; the chelge are 

 generally very curved, so that in some cases they only 

 meet at the points (PI. XLYIII, figs. 4, 9), sometimes 

 the points even cross (PI. XLYII, fig. 7). The denti- 

 tion is usually carried by a median ridge on the inside 

 of the chela (PL XLYIII, figs. 4, 9). 



The Lingua is not, as a rule, particularly well deve- 

 loped, but is well seen in N. biverrucatus, &c., where 

 each side terminates in a strong tooth or hook. 



The Pseudo-stigmata are very large and pro- 

 jecting in most species, and the pseudo-stigmatic 

 organs are mostly of one of two distinct types, either 

 very short, with thin peduncles which project but 

 little, and almost globular, or shortly pyriform heads 

 (PI. XLYII, fig. 9; PL XLYIII, fig. 5), or long and 

 almost filiform (PI. XLYI, figs. 4, 11); but in the 

 group formed by N. tardus^ N. glaber, and JSf. mono- 

 dactylus no external pseudo-stigmata of the ordinary 

 open tubular type are visible ; and it is very doubtful 

 whether the long setiform hair, which is present, is to 

 be regarded as a pseudo-stigmatic organ or an inter- 

 lamellar hair. 



The Lamellae are absent, or rather only represented 

 by two quite rudimentary ridges or folds of the cuticle ; 

 although this is the case, the lamellar hairs not only 

 persist, but assume very large dimensions, and in the 

 typical species spring from long chitinous apophyses, 

 which often project beyond the tip of the rostrum 

 (PL XLYIII, figs. 1, 7 ; PL XLYII, fig. 2). 



The Tectopedia are scarcely developed at all. 



The Apodemata are singular but instructive ; they 



