484 BRITISH ORIBATID.E. 



are mere infoldings of the cuticle, the two sides of 

 which, being scarcely anchylosed, except just at the 

 exterior, remain very loose and open. The cuticle 

 of the sternal surface between these apodemata is 

 bowed outward, giving the appearance of fixed coxae, 

 and they have been regarded as such by Nicolet and 

 others, but dissection does not seem to me to support 

 the idea, as they are only bendings outward of the 

 same cuticle that is bent inward to form the apode- 

 mata, with which they are continuous. 



The Sternum is usually scarcely developed at all, 

 except as a flat or depressed portion of the cuticle. 



The Legs are usually short, broad, and somewhat 

 flattened, almost always rough ; in a few species (as 

 N. palustris, &c.) they are rather longer. The short- 

 ness of the legs attains its maximum in N. monodac- 

 tylus (PI. XLY, fig. 11), where the fourth pair scarcely 

 reach beyond the commencement of the genital plates, 

 and the third and fourth pairs are set quite under the 

 abdomen. The first pair of coxae in this genus, in- 

 stead of being the spoon-shaped pieces almost wholly 

 sunk within the acetabulum, which is the usual form 

 in the family, are generally tubular projecting pieces, 

 similar to the other joints. The coxjb of the third and 

 fourth pairs, especially the latter, are, in some species, 

 set upon tubular projections of the ventral surface 

 {N. palustris, N. sylvestris, &c.). If these are to be 

 regarded as projections of the ventral plate, as they 

 probably are, then they are exceptional ; if, on the 

 other hand, they are to be regarded as fixed coxse, they 

 would be equally exceptional, and then we should have 

 to admit that in these legs the trochanter is separate 

 from the femur, as there are five free joints as usual. 

 The femora are ordinarily the thickest and broadest 

 joints, and have a short portion of the proximal ends 

 much thinner and turned nearly at right angles. The 

 genuals and tibias are generally of about equal length ; 

 the tarsi vary very much, they are generally almost 

 straight and more or less blunt-ended, and often have 



