DOROPYGUS. 139 



very large, bearing several long, stout, and often 

 densely plumose setae (fig. 2), and two slightly curved 

 spines ; second, third, fourth, and fifth joints succes- 

 sive more slender, sixth and seventh of about equal 

 width, last three much smaller; the whole limb is 

 beset with stout setae which, except on the basal joint, 

 are only slightly or not at all plumose. Terminal 

 claw of the posterior antenna (fig. 3) much shorter 

 than the second joint. Both branches of the first 

 pair of feet (fig. 5) 3- jointed, their setae, like those of 

 the other feet, finely plumose ; marginal spines entire 

 at the edges. The articulations of the outer branches 

 of the second, third, and fourth pairs of feet (figs. 

 6, 7) are very oblique, each segment being contracted 

 at base and dilated at apex, as in D. Normani ; the 

 maxillae agree in every respect with D. Normani, but 

 the second pair of foot-jaws (PL XXXIII, fig. 15) are 

 like those of D. pulex, to which species also the caudal 

 segments closely approximate in character. The 

 species seems in fact to occupy an intermediate 

 position between D. pulex and D. Normani. Fifth foot 

 simple, bearing two short setae at the apex, which is 

 obliquely truncate (fig. 8), inner margin ciliated. 

 Last abdominal segment (fig. 9) partially divided so 

 as to form two subtriangular portions; caudal seg- 

 ments elongated, much longer than the united lengths 

 of the two preceding, convoluted at the apex, and 

 bearing three minute terminal hairs. Length yth of 

 an inch (4 mm.). 



