ART. 8. MILLIPEDS OF CENTKAL, AMERICA — CHAMBERLIN. 53 



127. TUNODESMUS ORTHOGONUS, new species. 



Plate 19, fig. 10; plate 20, figs. 1-9 ; plate 21, figs. 1, 2. 



Dorsum brownish, most metatergites fuscous caudally and across 

 keels mesad of the caudolateral corners and processes, which are 

 pale ferruginous. A series of narrow light spots form a median 

 longitudinal line on dorsum. Venter and legs paler, brownish yellow. 

 Head dark over vertex and f rons, elsewhere pale. Antennae fuscous, 

 the last joint pale. Head with a fine sulcus across vertex and two 

 principal setae each side of it. Collum convexly arched, the keels 

 continuing nearly the same arc as the dorsum and descending down 

 on each side of the head, which they greatly exceed. Anterior mar- 

 gin straight across middle region, laterally curving back around 

 anterior corners of keels. Posterior margin arcuate, being concave 

 at middle and convex each side of middle (pi. 20, figs. 1, 2). Surface 

 of all segments wholly smooth. Caudal angles of keels of second 

 and third segments subrectangular. Posterior angles of other keels 

 acute, becoming more and more produced in going caudad. Anterior 

 margins of keels bowed convexly; anterior corners rounded; a single 

 small serration on lateral margin; posterior margin also convex 

 at base, wholly smooth (pi. 20, figs. 3, 4). Sternal processes or 

 tubercles present both at base of anterior and of posterior legs, the 

 latter the larger. These tubercles j)resent forward to fifth or sixth 

 segment, but of reduced size in the anterior region. Tubercles 

 densely pilose. Posterior tubercles of last two or three segments 

 more elongate and slender (pi. 20, fig. 5). 



Anal scale somewhat triangular, but caudally rounded and notched 

 on each side near level of seta, the sides also convex (pi. 19, fig. 10). 



A leg of male is shown in outline in plate 20, figure T. 



Gonopods represented in plate 20, figure 9, and plate 21, figures 

 1,2. 



Length, male, 21 mm.; width, 4.8 mm. 



Locality. — Guatemala: San Rafael, one male (O. F. Cook, June 

 4, 1914). 



Type.—Q^i. No. 851, U.S.N.M. 



128. TUNODESMUS LAMINIGER, new species. 



Plate 21, figs. 3-5. 



Coloration in general as in the preceding species, but the light area 

 of keels not extending so far forward, typically restricted to the 

 caudal process. The keels are similar to those of orthogonus., but the 

 anterior margin curves more strongly forward, while the posterior 

 margin is proximally more strongly convex (pi. 21, fig. 3). 



The species is most readily distinguishable by the structure of 

 the gonopods of the male. The anteriorily directed end of the distal 



