40 IOWA STUDIES IN NATURAL HISTORY 
Genus AMNESTUS Dallas 
1851. Amwnestus Dallas, List Hem., I, 110 and 126. 
This is one of the smaller genera of Cydninae, eight forms only 
being mentioned by Signoret. Three forms have been recorded 
from North America all of which have also been found in Iowa. 
The members of the genus are common to the Nearctie and Neo- 
tropical regions and are most at home in more or less sandy situ- 
ations. The principal generic characters follow: 
Body subquadrate, more convex below than above. Head small, longer 
than broad; anterior margin semicircular, armed with short, stout teeth, 
four of which are on the tip of the tylus which is longer than the juga. 
Eyes large, prominent. Second antennal segment very small, slender, the 
fourth and fifth segments long and very slenderly articulated. Rostrum 
very long and slender, the basal segment longer than the bucculae which 
are short and somewhat rounded. Pronotum a little wider than long, the 
anterior portion of the disk convex, the anterior angles broadly rounded; 
a transversely impressed line behind the middle. Prosternum raised and 
bounded on either side by a broad arched plate. Ostiolar canal long, 
slender, extending almost to outer margin of episternum, the sides ele- 
vated. Scutellum small, triangular, equilateral, the tip acute. Corium 
short, broad, the posterior margin sinuate, the costal margin arcuate 
towards apex; membrane very long, white, surpassing the abdomen and 
with two to four indistinct longitudinal veins. Legs slender, not closely 
spined; tarsi short, slender and pubescent; anterior tibiae enlarged and 
compressed at tips; a single row of stout spines on outer edge, gradually 
increasing in size towards apex which is furnished with four spines; sev- 
eral slender and very oblique teeth along inner margin on the under side; 
apical half of anterior femora distinctly enlarged. 
Key to the species 
Form somewhat more convex; color darker; length, 3.5-4.5 
WM 6 CES Ae A AU ee spinifrons 
Form less convex; color paler; length, 2.0-2.75 mm. 
Juga each with four spines . ....... 4. =. 2422 eee pusillus 
Juga each with five spimes .....5..........- 3 eee pallidus 
Amnestus spinifrons (Say) (PuaAte II, Ficures 5, 7 and 8, and 
PuaTE V, FIGURE 3) 
1883. Amnestus spinifrons Signoret, Ann. Soc. Ent. France, III, Ser. 6, 367, 
PIE 0; fig. 1.92: 
1911. Amnestus spinifrons Zimmer, Univ. Neb. Contrib. Dept. Ent., no. 4, 23. 
1877. Cydnus spinifrons Uhler, Bull. U. S. Geol. Geogr. Surv., III, 370. 
1825. Cydnus spinifrons Say, Journ. Acad. Nat. Sci. Phila., IV, 316. 
1876. Amnestus spinifrons Stal. Svensk. Vet. Handl., 16, no. 4, 21. 
1859. Cydnus spinifrons Say, Compl. Writ., II, 242. 
1851. Ammnestus spinifrons Dallas, List Hem., I, 126, Pl. 3, fig. 2. 
