NO. 14 MILLIPEDS OF WEST INDIES AND GUIANA LOOMIS 39 



desmidae, but the tiny, i8-segmented body distinguishes it from all 

 other forms except the i8-segmented Hexadesmus, which has the 

 dorsal setae slender instead of definitely clavate. 



Description. — Body very small, about eight times as long as broad ; 

 composed of but i8 segments ; dorsum lacking tubercles or convex 

 areas but definitely reticulated and with transverse series of strongly 

 clavate setae. 



Head with no median furrow evident, the surface reticulated and 

 with many tiny, erect bristles, those of the vertex shorter than else- 

 where. Cardo of each mandible with short bristles similar to those 

 of the vertex. Antennae strongly clavate, with joint 6 longest and 

 broadest ; joints 4, 5 and 6 each with a very long extremely fine hair 

 on the outer side near the end. 



First segment oval ; narrower than the head or the ensuing seg- 

 ments ; surface relatively coarsely reticulated, as is the surface of 

 all the other segments ; a series of 10 large, clavate bristles along the 

 anterior margin, and behind this is a median series of 4 similar bris- 

 tles, and a third row of bristles along the posterior margin. 



Second segment with the lateral carinae a little longer than those 

 of the next two segments, distinctly produced forward, the carinae 

 of the ensuing segments decreasingly so ; anterior and posterior corners 

 of all carinae rounded, except on the three segments preceding the 

 last, which have the posterior corners acute and moderately produced 

 backward ; lateral margins simple, convex in outline. 



Posterior subsegments moderately convex, with a distinct trans- 

 verse depression ; surface reticulated ; the lateral carinae slightly de- 

 pressed, not very strongly produced. Along the anterior margin of 

 each segment is a series of 10 erect, strongly clavate setae, and a series 

 of 8 similar ones along the posterior margin, the bristles of both series 

 directed forward. On the four segments in front of the last some of 

 the bristles of the anterior row are moved back and form a submedian 

 row. Penultimate segment with six very long, slightly clavate hairs 

 projecting straight back from the posterior margin. 



Last segment as long or longer than the penultimate segment ; defi- 

 nitely produced into a slightly down-curved, papillate mucro. 



Repugnatorial pores large, rimless, opening from the top of a slight 

 conic swelling of the dorsal surface close to the posterior corner of 

 segments 5, 7, g, 10, 12, 13, 15, 16, and 17. 



Anal valves moderately convex, with raised margins. 



Preanal scale long, rounded-triangular. 



Sterna wider than the length of the first joint of a leg ; crossed each 

 way by a deep median depression. 



