333 



of the thorax gives origin, beneath, to a pair of ponderous 

 angulated legs, composed of the ordinary parts. The 

 three anterior pairs project themselves forward, and are 

 closely compressed upon the inferior surfaces of the three 

 foremost segments ; they are monodactyle, witli the nails 

 incurved upon the anterior edges of the rather largely in- 

 flated penultimate joint. Each joint is furnished at its 

 articulating extremity with rigid spines ; the inner edges 

 of the penultimate joint, together with those of the three 

 adjoining, are provided with a double row of tufted cilia, 

 disposed diagonally, and much resembling in appearance 

 the arrangement of hairs in an ordinary brush. The four 

 posterior pairs of legs are directed Imckwards, strongly 

 triangulate, stout and ponderous, terminating by a slightly 

 curved nail ; their length is nearly equal, but they gradu- 

 ally increase in thickness as they recede toward the tail. 

 The basal joints are large and inflated ; the remainder 

 regularly angulate. The extremities of the articulating 

 joints, and edges of the two inferior angles, are each pro- 

 vided with a series of tufted and rigid spines. 



The post-abdomen is composed of five segments. The 

 four anterior ones are much smaller than those which con- 

 stitute the thorax, but greatly resemble them in form, 

 being ornamented on their superior surfaces with similar 

 insculptations, though but slightly defined. Each of these 

 segments is provided beneath with a pair of articulated 

 pedicels, which furnish a support to the bifoliated bron- 

 chial leaflets. These leaflets are arranged longitudinally 

 one upon the other, and are entirely concealed by the 

 biarticulated plates of the caudal segment ; they are sub- 

 ovate and elongate ; the outward ones smaller than those 

 which they cover, and are nearly surrounded by a fringed 

 cilia, most conspicuously developed along their inner mar- 

 gins. The second pair are each supplied with an elonga- 

 •ryle, extending almost to the termination of the 

 1 segment. The terminating segment is large and 



