BY VERA A. IBWIN -SMITH. 771 



individuals (PI xliv., xlv., i.>-.). The seta^ (0-01 8 mm. to 022 

 mm. long) are all compound, each consisting of a stout, tubulai- 

 rod inserted by a broad base in the cuticle, bearing, at its distal 

 end, a very small, leaf-like, movably-jointed segment (PI. xlv., 

 fig. 26). They are separated by fairly wide intervals posteriorly, 

 but are more closely crowded anteriorly, especially in the older 

 individuals. In front of each inner row, and directly continuous 

 with it, there are, in individuals of all ages, three or four, small, 

 simple setjie of the same length (0*007 mm.) as the trunk hairs 

 lying in front of them (PI. xlv , s.). The trunk-hairs continue 

 the ventral rows to the anterior end of the trunk (PL xlv., t.h.). 

 The two outer rows of locomotor setse begin, as a rule, about 

 three setae further back than the inner rows (PI. xlv., o.r.), and 

 are situated ventro-laterally, separated by a fairly wide interval 

 (0-018 mm.) from the inner rows. In the male (PL xlv,), they 

 consist of simple and compound setse, alternating fairly regularly, 

 there being, in the adult worm, about twelve compound and 

 seven simple setye in each row. The compound seta3 (c.s.) are 

 quite similar in size and character to those of the inner rows; 

 the simple setae {s.s.) are the same length, but are very slender 

 and taper to a tine point. In the female, the outer rows are 

 composed entirely of compound setae, about twenty-one in number 

 in the adult (PI. xlv.j. The inner rows cease before the anus, 

 but the outer rows are continued back on either side of it, almost 

 to the junction of the trunk with the tail. In the female, the 

 postanal portion of the row consists of three or four compound 

 setie exactly like those further forward (PL xlv., fig.2«). But, in 

 the male, the compound setae stop some little distance in front 

 of the anus, and the posterior portion of the row consists of eight 

 or nine simple setae, shorter than those between the compound 

 setae, but stronger, stouter, and very sharply pointed. The last 

 pair are frequently inserted right on the tail-point (PL xlv., fig. 

 \a). They appear to correspond closely with the double row of 

 setie present in the region of the anus, in some of the free-livin^^ 

 marine Nematodes, where they constitute one of the external 

 characteristics of the male. They are described by Bastian(ll) 

 for the genera ^?i<icamrt, Eiiophis, and Coiiteaonio: and in greater 



