a Family of Thysauura. 373 



the remarkable framework for the support of the organs of the 

 mouth, which he has probably not observed, as he does not 

 mention it. I have distinctly observed the appendages on the 

 underside of the abdomen, corresponding to those of the Lepis- 

 mse, which Mr. Haliday failed to discover on his specimens ; 

 and I interpret the two chitinized plates on the underside of the 

 tenth abdomen-ring as the separated halves of the ventral shield 

 — not, with Mr. Halida}^, as the inflected margins of the dorsal 

 shield. Several minor points of divergence will appear from 

 the above description. 



Campodea, Westw. 



Cerci longi, multiarticulati, filiformes. 



Segmentum p^enultimum longitudine segmenti ultimi, scuto 

 ventrali integro. 



Mandibulse apice compressse, dentatse, appendice lamelliformi 

 instructse. 



Mala interior maxillse in dentes octo incisa. 



Palpi maxillares inarticulati. 



Palpi labiales breves, fere membranacei, setiferi, duas lougas 

 setas ensiformes apice gex'entes. 



Verrucse duse setiferse pone labium. 



Antennae filiformes vel submoniliformes. 



Oculi nuUi (vel seni,congregati,evanidi^). 



Unguiculi curvati, ad basin processibus binis longis^tenuibus, 

 curvatis instructij^. 



Spiracula terna. 



The mandibles are shorter and more powerful than in Japyx; 

 their apex is more compressed, almost cuneiform, with the ante- 

 rior edge oblique, dentate, and a sort of grinding-surface along 

 the inner edge of the apex. At the base of this grinding-surface 

 a small, thin, triangular lobe, with deeply incised fore margin, 

 articulates with the mandible. The muscles of the mandibles 

 are also upon the whole more powerful than in Japyx, and they 

 are disposed as in that genus. 



The maxillae are somewhat less complicated than in Japyx; 

 the inner lobe is less elegant ; the subsidiary lobes are more in 

 number, but not themselves subdivided, the two outer ones 

 being the most powerful, the others with thin foliaceous apices. 

 The outer maxillary lobe is, as in Japyx, foliaceous, with a conical 

 protuberance on the upperside. The palpus is inarticulate, 

 and in a great measure united with the maxilla without distinct 

 'palpiger. 



The lingua is large, oval ; the pai'aglossse large and flat ; they 

 cover the lingua almost entirely from above, and surround also 



