56 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.60. 



much exceeding the head in width and as wide as the second tergite. 

 As long at base of keels as at middle. Anterior margin weakly con- 

 vex, with anterolateral corners of keels rounded evenly and caudal 

 corners subrectangular or slightly acute. Caudal margin concave at 

 middle, convex each side of this, and then straight or a little concave 

 at each end (pi. 22, fig. 3). Keels'in general high on body, horizon- 

 tal or a little raised. Keels of second, third, and fourth segments 

 longer than median region of metatergites. Margins of keels raised 

 in front and behind as well as laterally; the lateral margins more 

 thickened, the thickened greatest about cores, which are sunk in the 

 lateral edge, the thickening decreasing gradually each way from this. 

 All anterior corners rounded. The posterior corners rectangular 

 back to the fourteenth segment, inclusive. Caudal corners of fif- 

 teenth and sixteenth keels a little broadly produced, those of seven- 

 teenth more produced, and those of eighteenth strongly so, while 

 those of the nineteenth are much smaller and narrower, though also 

 strongly produced (see pi. 22, figs. 4 and 5). Margins wholly smooth. 

 Metatergites with only a very shallow transverse depression; the 

 entire surface finely granular, with a series of well-separated, larger 

 granules along caudal margin and one of a few, much more widely 

 separated granules across anterior border. Anal tergite triangular, 

 distally narrowly truncate, and on truncate surface bearing four 

 setae. Anal valves margined; surface a little rugose and with fine 

 granules like those of dorsum (pi. 22, fig. 5). 



Anal scale triangular, the caudal angle a little rounded (pi. 22, 

 fig. 6). 



Legs very long, extending widely beyond the sides of the body. 

 Proportions of joints as shown in plate 23, figure 2. 



Gonopods as represented in plate 23, figures 3 and 4. 



Length, 24 mm. ; width, 3.6 mm. 



Locality. — Guatemala : San Rafael, five males (O. F. Cook, June 4, 

 1914). 



Type.— Cat No. 854, U.S.N.M. 



Genus ACERATOPHALLUS Carl. 



134. ACERATOPHALLUS UNICOLOR Carl. 



Aceratophallus vnicolor Carl, Rev. Suisse Zool., 1902, vol. 10, p. 609, pi. 2, 

 figs. 35, 36. — Brolemann, Ann. Soc. Ent. France. 1905, vol. 74, p. 345, pi. 

 8, figs. 6, 7.— PococK, Biol. Centr.-Amer., Diplop., 1909, p. 182, pi. 14, fig. 2. 



Localities. — Costa Rica : San Jose, La Uruca. 



135. ACERATOPHALLUS LAMELLIFER Brolemann. 



Aceratophallus unicolor lamellifer Brolemann, Ann. Soc. Ent. France, 1905, 



vol. 74, p. 346, pi. 8, figs. 1-5. 

 Aceratophallus lamellifer Pocock, Biol. Centr.-Amer., Diplop., 1909, p. 183. 



Locality. — Costa Rica: San Jose. 



