86 Annals of the Carnegie Museum. 



Genus Mastusia Stal. 

 Mastusia StAl, Bihang. Svensk. Vet.-Akad. Handl., V, no. 4, pp. 39, 84 (1878). 



The genus Mastusia is entirely confined to South America, at least 

 so far as known at present. Two species have been described pre- 

 viously, and now a third is added. The relationship of the present 

 species to the other described forms is shown by the annexed synop- 

 tical table. 



Synopsis of the Species of Mastusia. 7 



A. Size larger (30 mm. or more in length). 



b. General color olivaceous. Tegmina abbreviated, not greatly, if any, longer 

 than -the pronotum ( 9 32 mm. in length). Peru., .quadricarinata Stal. 

 bb. General color grass-green. Tegmina more elongate, nearly the length of 

 the abdomen (cf 30 mm. in length). Upper Amazon. 



spectabilis Bolivar. 



AA. Size smaller ($26 mm.). Tegmina and wings two-thirds the length of the 



abdomen. Wings blue caruleipennis sp. nov. 



125. Mastusia caeruleipennis sp. nov. 



A medium-sized moderately robust species, in which the head is 

 quite noticeably wider than the anterior edge of the pronotum. The 

 tegmina and wings two-thirds the length of the abdomen, the former 

 brown with a narrow pallid longitudinal line along the angle, the latter 

 caerulean. Antennae with the apical joint pallid. 



Head rather large, somewhat obese, rounded on sides and occiput, 

 considerably higher than long; the eyes fairly prominent, elongate 

 oval, somewhat pointed above, a little longer than the anterior edge 

 of the cheeks below them; vertex fairly wide, of the same width as 

 the frontal costa between the antennae, and provided with a deep 

 coarse pit, which separates it from the fastigium; the latter short, fully 

 twice as wide as long, its surface back of the lateral and anterior 

 margin gently depressed; lateral ocelli large, ferruginous, located on a 

 small defiexed triangular area just in advance of the upper portion of 

 the eyes. Face somewhat oblique, viewed in profile straight; the 

 frontal costa prominent, widely sulcate throughout, continued to the 

 clypeus; lateral or facial carina? prominent, divergent below, and 

 reaching from the posterior extremity of the fastigium to the base of 

 the mandible. Antennae filiform, about as long as the head and 



7 The Mastusia koebelei Rehn belongs to a new genus {Eumastusia) more closely 

 related to Oxybleplella Giglio-Tos than to Mastusia, as will be recognized by the 

 widely transverse prosternal spine and other characters. It may be considered 

 as the type of that genus. 



