200 OETHOPTEEA. 



the eyes. General colour testaceous, cinereous, dark 



olivaceous, or even ferruginous Calamacris, Eehn *, 



bb. Body robust or even obese, frequently compressed. Tegmina, 

 when present, elongate. 

 c. Pronotum acutely tectiform. Antennas triquetrous, dilated 

 at the base. Tegmina and wings wanting. Cerci of male 



branched Xyronotus, Saussure. 



cc. Pronotum obtusely tectiform or rounded. Antennae filiform. 

 Cerci of male simple. 

 d. Tegmina ampliated at the apex. Pronotum gently sinuate 



behind Sphenarium, Charpentier. 



dd. Tegmina ampliated at the base. Pronotum strongly 



sinuose behind , Prosphena, Bolivar. 



CALAMACRIS, Rehn. 



Calamacris, Eehn, Proc. Acad. Nat. Sci. Philad. 1904, p. 529. 

 Atyphoscirtus , Bruner (MSS.). 



This genus of locusts is confined to the warmer parts of the arid regions of North 

 America. Representatives occur from Southern Arizona in the United States to the 

 State of Jalisco in Mexico. Five forms are represented either by specimens at hand 

 or by published descriptions. They may be separated briefly as follows : — 



Table for separating the Species of Calamacris. 

 A. Body without definite, or with very faint, supplemental longitudinal 

 carinas on the dorsum of the meso- and metathoracic and basal 

 abdominal segments. 

 b. Tegmina present, very small and simple. Fastigium of the vertex 



rouuded. (Jalisco.) 1. clendoni, Eehn. 



bb. Tegmina wanting. Fastigium of the vertex acuminate. (Lower 



California.) [2. californica, sp. n.] 



AA. Body provided with conspicuous supplemental longitudinal carinas 

 on the dorsum of the meso- and metathoracic and basal abdominal 

 segments. 

 b. Antennas exceptionally heavy, widely dilated at the base. Face 



very strongly oblique. (Lower California.) ....... [3. mexicana, sp. n.] 



bb. Antennae rather slender, only gently dilated at the base. Face less 

 strongly oblique. 

 c. Eyes moderate, not prominent. The fastigium of the vertex 



rounded. (Lower California.) . [4. palmeri, sp. n.] 



cc. Eyes large and very prominent. The fastigium of the vertex 

 acuminate, slightly depressed. (Southern Arizona and pro- 

 bably N. Mexico.) 5. oculata, sp. n. 



* This genus is the same as Atyphoscirtus, two species of which are figured on Tab. IV. figg. 24, 25, 26. 



