262 Annals Entomological Society of America [Vol. XI, 



Hyalymenus Amyot et Serville. 

 Logotype dentatus Fabricius. 



Hyalymenus Amyot et Serville (1843) 223; Dallas (1852) 467; Herrich-Schaeffer 



(1853) 243; Stal (1867) 542, (1870) 210, (1873) 90; Distant (1881) 156. 

 Tivarbus Stal (1859a) 459. 

 GaJeottus Distant (1893) 459. 



The genus Hyalymenus as now limited includes all American 

 species of Alydini in which the posterior coxae are subcon- 

 tiguous and the posterior tibiae, compressed, curved, and armed 

 with a strong tooth at the apex. The former character separates 

 it from Apidaurus, of which the species conspersus is to be 

 found in Mexico and South America. 



No representatives of subgenus Hyalymenus in which the 

 corium is transparent like the membrane, are known north of 

 Central America and the Antilles. Our species all belong to 

 subgenus Tivarbus Stal. 



KEY TO SPECIES OF HYALYMENUS. 



a. Male with posterior tibiae serrate on the anterior margin near the middle; 



pleura with two to three large shining flavous spots; antennge refuscent. 



b. Hv:mera1 spines not very long, width between apices not over one 



and one-third times as great as width of head; posterior femora 



gradually darker toward tip tarsalus Fabr. 



bb. Humeral spines very long, width between their apices over one and 

 one-half times width of head; posterior femora flavescent, 



vSuddenly dark ferrugineous at tip longispinus Stal 



aa. Male with posterior tibia? entire; pleura without shining fiavous spots; 



antennae black pulcher Stal 



(). Hyalymenus tarsatus Fabricius. 



Alydus tarsatus Fabricius (1803) 250. 



Al'ydus atratus Fabricius (1803) 257. 



Alydus diversipes Westwood (1842) 19; Dallas (1852) 477. 



Alydus affinis Westwood (1842) 19; Dallas (1852) 477. 



Alydus ohscurus Westwood (1842) 19. 



Alydus sinuatus Herrich-Schaeffer (1846) 98; nee Fabricius. 



Alydus recurvatus Herrich-Schaeffer (1846) 98. 



Alydus pallens Dallas (1852) 476. 



Tivarbus tarsatus Stal (1859) 460. 



Camptopus pectoralis Stal (i860) 34. 



Hyalymenus tarsatus Stal (1868) 62, (1870) 212; Uhler (1876) 294i; Distant (1S81 ) 156; 



Barber (1906)^; Snow (1907)'. 

 Camptopus tarsatus Walker (1871) 162. 

 Galeottus formicarius Distant (1893) 459. 

 Tivarbus diversipes Uhler (1894) 236. 



Description. — Color varying from pale flavescent to dark fuscous 

 or nigricant; thorax with a small white spot near posterior margin 

 of sides of pronotum and two or three large lateral white spots on the 

 pleura near coxae; abdomen with a row of medio ventral white spots. 



Abdomen depressed, third to sixth segments in the male each amied 

 with a lateral spine, those of fourth and sixth longer than others. Male 

 with the posterior femora armed at middle with a prominent spine and 



