ART. 18 NEW GENERA OF MILLIPEDS COOK AND LOOMIS 11 



to an acute angle below, but showing no tendency to form a pro- 

 jecting beak. 



Description, — Body extremely slender, monilifoirm, about fifty 

 times as long as broad; composed of a very large number of seg- 

 ments, in the longest specimens approaching 200; dorsum strongly 

 convex, nearly semicylindrical ; the surface shining, moderately 

 hirsute. 



Head triangular-cordate in outline, resembling that of Polyzoniv/m 

 and without any suggestion of a beak, the sides continuous and 

 sharply converging to a rather blunt angle, but not produced into 

 a snout. Position of the head nearly vertical to the body, not 

 reflexed under the body. 



Antennae inserted at the sides of the head, abruptly capitate- 

 clavate, subgeniculate ; joints 1 to 4 very small, joints 5 and 6 

 abruptly thicker and larger, held parallel to the sides of the head; 

 joint 6 the longest, but scarcely as broad as joint 5; joint 7 broad 

 and short. 



First segment slightly narrowed, about half again as long as the 

 second ; oblong, the lateral margins evenly rounded, anterior margin 

 nearly parallel with the posterior; the surface nearly even, lacking 

 the abrupt convexity of the posterior subsegments on the rest of 

 the body; segments 2 to 4 shorter than the following, the trans- 

 verse constriction with an irregular row of rounded tubercles on the 

 anterior slope; surface of anterior subsegments rather coarsely re- 

 ticulate^ surface of posterior subsegments finely hirsute, each of the 

 hairs subtended by a short sublunate transverse groove, giving the 

 general effect of an indistinct network; supplementary margin dis- 

 tinct, with regular truncate divisions. 



Eepugnatorial pores difficult to detect, located on sliglit promi- 

 nences near the posterior margins of the segments, not close to the 

 lateral margins, pores of segment 5 in the same position as the 

 others; lateral sutures open, bordered by slight parallel ridges; 

 surface of pleurae with a rather open reticulation, sparsely hirsute 

 along the posterior margins. 



Last three segments somewhat longer than the preceding; the 

 anal segment nearly as long as the penultimate, the sides converg- 

 ing to a broadly rounded apex, even with the valves, not projecting ; 

 surface of the anal valves rather strongly and evenly convex, the 

 margins not prominent; preanal scale not distinct. 



Legs rather short, scarcely exceeding the sides of the body, the 

 basal joints prominent and swollen on the inner side, sometimes 

 with an extruded membrane or exudate, nearly in contact on the 

 median line. 



This genus separates at once from Siphonacine and Siphonophora 

 by the 9,bsence of a beak. The antennae are different from those of 



