250 PROCEEDINGS OF THE NATIONAL MUSEUM vol. io« 



externomedian apical spur equaling half the length of the metatarsus; 

 superointernal apical spur extending to the apex of the metatarsus. 



The right elytron is wanting; left elytron presenting only three 

 straight, equidistant veins, without transverse veinlets. Wings very 

 long. 



Length of body 5.0 mm.; length with wings 10.5 mm.; posterior 

 femur 4.2 mm.; ovipositor 2.4 mm.; elytra 2.6 mm. 



Remarks: This species is very close to the preceding; it is of a 

 more uniform coloration, with concolorous last joint of maxillary 

 palpi, which is also longer and less strongly enlarged at apex; spines 

 and spurs of the posterior tibiae much longer. 



Family Mogoplistidae 



Key to the American genera 



1. Posterior metatarsus very long, almost unarmed above. 



Cycloptiloides Sjostedt 

 Posterior metatarsus armed with spinules on the superior margins .... 2 



2. Anterior tibiae without tympana 3 



Anterior tibiae provided with an auditory tympanum on the internal face . . 4 



3. Apical spurs of the posterior tibiae very long Microgryllus Philippi 



Apical spurs of the posterior tibiae short. Oligacanthopus Rehn and Hebard 



4. Elytra of the male completely hidden under the pronotum. 



Ectatoderus Guerin 

 Elytra of the male partly visible 5 



5. Pronotum of male elongate, rounded behind; elytra with periphery only visible 



beyond pronotum Cycloptilum Scudder 



Pronotum of male almost truncated behind; tegmina almost completely 

 visible Omebius Guerin 



Family Pentacentridae 



Key to the American genera 



1. Posterior metatarsi very long, cylindrical, unarmed above 2 



Posterior metatarsi compressed, denticulated above 3 



2. Eyes well developed; ocelli present; anterior tibiae perforated; elytral venation 



normal Trigonidomimus Caudell 



E5'es degenerated; no ocelli; anterior tibiae without tympana; elytra corneous, 

 without distinguishable mirror Tohila Hubbell 



3. Elytra of the male feebly differentiated, showing the anal vein and one oblique 



vein; posterior tibiae witli four or five spines on each margin, six apical 

 spurs; posterior metatarsi twice as long as the other joints united. 



Aphemogryllus Rehn 



Elytra similar in both sexes, with longitudinal, parallel veins; posterior femora 



short without filiform apical part; posterior tibiae armed with three spines 



on each margin and five apical spurs; matatarsi not so long, dilated in the 



male Nemobiopsis Bolivar 



