REHN AND HEBARD 225 



to their very long and lever-like caudal limbs, as a single bound 

 will often place them in a place of safety on a chamisal bush 

 well out of reach, except by a new and cautious advance through 

 the heavy brush, often with similar disappointing results. Steady 

 and persistent beating, while by no means easy on account of the 

 character of the cover, is probably the best method of securing 

 series of these interesting little grasshoppers. 



The two genera found in our territory may be distinguished 

 by the following features: 



A. Form slender. Head narrow in proportion to depth. Fastigium, in both 

 sexes, projecting a distance at least one-third of width of same, when seen 

 from dorsum, narrower; in profile fastigial angle is acute. Frontal costa very 

 narrow and subequal mesad and ventrad, ^videned briefly dorsad. Antennae 

 with tooth on ventral surface of tenth segment.^ Lateral lobes of pronotum 

 with ventro-caudal angle rounded rectangulate. Cerci of d^ compressed 

 and falcate ventrad in distal section. Subgenital plate of cT with a median 

 linguiform process directed dorso-cephalad from disto-dorsal margin, which 

 is entire. Limbs more elongate and slender. Morsea Scudder 



AA. Form relatively robust. Head broader than in alternative. Fastigium, 

 in both sexes, projecting less than one-third of the width of the same, when 

 seen from the dorsum, broader; in profile fastigial angle is right-angled. 

 Frontal costa of average width, widening dorsad. Antennae with tooth on 

 ventral surface of ninth segment. Lateral lobes of pronotum with ventro- 

 caudal angle not rounded, rectangulate. Cerci of cf simple, styliform. 

 Subgenital plate of cf without a median linguiform process, disto-dorsal 

 portion of plate made up of two lateral, mesad attingent sections. 



Psychomastax new genus 



In the series before us are present three hundred and eight 

 specimens of the subfamily from the area under discussion, by 

 far the greater portion belonging to the genus Morsea. As indi- 

 viduals of this group are very active and elusive, the series repre- 

 sents a far greater amount of persistent work than the number 

 alone would suggest to those unacquainted with these active 

 bush-loving insects. 



' In Morsea this tooth occasionally appears to be on the eleventh segment, 

 but this will be found to be due to an adventitious and incomplete division of 

 the third segment . 



TRANS. AM. ENT. SOC, XLIV. 



