of Dytiscidcs Darwinians. 17 



transverse, 6to — lOmo transversis qiiinto majoribus, ultimo 

 subulato 2 prsecedentium longitudinem subaequante. Paljn 

 viaxillares extcrni articulis 1, 2 et 3 breviusculis, transversis, 

 obconicis ; 4to maximo, elongate, ventricoso, apice atlenuato ; 

 p. m. interni subulati attenuati, articulo primo elongate sub- 

 cylindrico, 2do dimidio breviori. Mentum lobo intermedio 

 dentiformi minuto acuto, lobis lateralibus subacutis. Palpi 

 lahiales articidis 1, 2 et i], brevibus transversis, 4to maximo 

 ovato obtuso. Scutellum inconspicuum. Pedes abbreviati, 

 tarsis posticis 4-articulatis. 



[PI. 1, fig a, mandible; 5 6, maxilla j 5 c, labium; bd, antenna; 5 e, fore 

 leg; 5/, hind leg.] 



Closely allied in appearance to Hijgrotus, Steph., but distin- 

 guished by the structure of its antennae and palpi. 



1. (23.) jD. nitida, Bab. (PI. 1, fig. 5.) 

 Rotundato-ovata, fusco-flava, elytris obscurioribus, antennis 



pedibusque flavis. (L. c. £ ; lat. J lin.) 

 Between orbicular and ovate, dusky yellow, convex above, 

 smooth and shining. Head smooth. Thorax transverse, short, 

 broadly emarginate in front; sides rounded, hinder margin sinuated, 

 disk punctured. Scutellum wanting. Elytra cordate, pointed, 

 rather deeply punctured. Body beneath dusky yellow, the breast 

 darker. Legs and antennae yellow. 

 Hab. Rio de Janeiro. 



VOL. III. 



