1028 FAMILY XXXV. — NERTHRID^E. 



rower than pronotum, conjointly oval, reaching tip of abdomen; disk dis- 

 tinctly not strongly concave, not punctate and without seta?, each with a 

 short oblong tubercle at middle of base, a larger obtuse one at middle and 

 a third, much smaller, close to suture at apical fourth. Connexivum 

 rather broadly exposed behind the sub-basal lobe of elytra, its margin 

 coarsely crenate. Apex of front trochanters forming a short bifid tooth. 

 Middle tarsi 1-jointed; hind tarsi 3-jointed, the third joint as long as 

 the others united. Genital plate of male concealed beneath the sixth 

 ventral. Other structural characters as above given. Length, 8.2 mm.; 

 width, 5 mm. 



Known only from two males taken March 21, 1911, from 

 the muddy margins of Arch Creek, Fla. This is probably the 

 Monoiiyx stygicus of Uhler (1884, 264) nee Say, and the Nerthra 

 stygica Say of Howard (1902, pi. XXIX, fig. 16) but, as pointed 

 out by Bueno (1905e) it is not Say's species which is described 

 below. However, Bueno is in error in supposing that the form 

 described by Uhler and figured by Howard is "either Mononyx 

 fuscipes Guer. or M. nepoeformis (Fabr.)," as those two species 

 are both true members of Mononyx, having the elytral mem- 

 brane present and overlapping. 



III. Nerthra Say, 1832, 37 ; I, 364. 



Differs from Glossoaspis by the characters given in key and 

 by having the front of head less vertical, more triangular and 

 tuberculate near apex ; ocelli very small, almost concealed by 

 the surface crust ; eyes shorter, more convex ; pronotum nar- 

 rower, twice as wide as long, its sides less broadly flattened 

 and median convexity less rugose ; elytra without a lateral ex- 

 pansion near base, the disk feebly convex instead of concave, 

 without distinct tubercles, but much roughened with oblique 

 lines of short acute elevations; front femora more swollen, the 

 raised inner margin of their groove wider or more elevated, but 

 confined to the apical half ; front tibiae and the single tarsal claw 

 shorter, the former carinate on outer side ; mesosternal tubercle 

 shorter, compressed, more inclined, its apex with several 

 bristles; hind tarsi 3-jointed, the joints subequal in length. 

 Genital plate of male deflected toward the right. One species 

 is known. 



1171 (1411). Nerthra stygica Say, 1832, 37; I, 364. 



Oval, broadly rounded behind. Dull blackish-brown above, fuscous- 

 brown beneath ; flattened sides of pronotum sometimes yellowish ; tibiae 

 and tarsi piceous. Apex of front of head with four small tubercles, the 

 median pair the longer. Pronotum with sides straight, subparallel, feebly 



