'. WEST INDIAN MILLIPEDS CHAMBERLIN. 7 



e." Number of somites forty-six or more. 

 f.^ Large species, from 75 to 170 mm. long. 

 g.^ Antennae long, reaching the third segment. 



R. domingensis Saussure. 

 g." Antennae short, scarcely surpassing the coUum. 



h.^ Length only to near 75 mm. ; width under 8 mm. ; somites 

 banded along posterior border with flavous or ferruginous. 



R. maltzani Pocock. 

 h.' Length above 125 mm.; width near 13 mm. or more; color 

 black or deep brown without bands of lighter color. 



R. haitensis (Gervais). 

 f.^ Smaller species under GO mm. in length. 



g^ Transverse suture strongly marked entirely across dorsum. So- 

 mites ferruginous beliind suture. (Haiti.) 



R. curtior Chamberlin. 



<7.° Trans\exse suture weak or obsolete above on most segments. 



h.^ A series of black transverse bands along the middorsum and 



on each side of this a longitudinal reddish or ferruginous 



stripe. (Jamaica) R. heteroscopus Chamberlin. 



//.^ With no such longitudinal stripes each side of a series of 

 middorsal black marks. 

 i.^ Somites above level of pores uniform dark brown or black, 

 not bordered caudally with lighter band ; width 3 mm. 



or scarcely more__ R. nigrescens ChamberLn. 



V Somites dorsally as well as laterally bunded with light color 

 along caudal border; width 4.5 mm. or more. (Posterior 

 male gonopods distally sti'ongly bifurcate, the prongs 

 equal In length, the ventral one evenly curved, abruptly 

 expanded at distal end where there are two raucra with 



convex edge between.) R. socius Chamberlin. 



d." Anal tergite surpassing the valves. 

 e.* Segments forty to forty-two. 



f.^ Legs long; antennae reaching the fourth somite. 



R. gracilipes Karsch. 

 A' Legs short; antennae not reaching to fourth somite. 



R. grenadensis Pocock. 

 c.* Segments fifty or more. 



f.^ Posterior part of the segments not elevated. 



R. arboreus Saussure. 

 ,r/\ Legs dark, uniform or nearly so. 



E,. arboreus arboreus, forma typica. 

 g.' Tarsi of legs reddi.sh or orange. 



/(..' Body light gray; usually a series of dorsal red spots; tarsi 



orange R. arboreus gundlachii Karscli. 



/t.' Body darker ; no dorsal spots ; tarsi reddish. 



R. arboreus krugii Karsch. 

 f.' Posterior part of segments elevated. 



f/.* Caudal process long R. niaci'opus Pocock. 



g." Caudal process sbort, but little exceeding valves. 



R. modestior Silvestri 



