PSEUDOSTIGMA. 63 



1. M. caerulatus ! 



Libcllula caerulata Drury, III, 75, tab. 1, fig. 1. Megaloprepus caerulatus 

 Ramb. ! Neuropt. 290, 1. Libellula coerulea Donovan, Nat. Reposit. 

 iv, 110. 



Black, beneath pale ; thorax with a humeral line, and two in- 

 feriorly lateral stripes, pale yellow ; feet black, femora inside and 

 tibiee outside pale yellow ; wings broad, hyaline, before the apex 

 a broad blue-black, transverse band, exteriorly, broadly margined 

 with milk-white and emarginated ; pterostigma large, oblong, black. 



Length 90 115 millim. Alar expanse 115 180 millhn. 



Hob, Mexico (Saussure) ; Yera Cruz (Salle) ; Guatimala; 

 Choco, ISTew Grenada (Schott) ; Honduras ; Bogota, Columbia. 



As yet, this is the most gigantic of the Odonata. 



The variety M. brevistigrna De Selys, from Bogota, differs in 

 being of a smaller size, the pterostigma small and the band of the 

 wings narrower. 



PSEUDOSTIGMA DE SELYS. 



Wings narrow, the reticulation of the posterior margin of the 

 wings simple, the areoles tetragonal, regular ; postcostal space 



with two series of areoles ; pterostigma irregular ; abdomen ex- 

 tremely long. 



1. P. accedens ! 



Pseudostigma accedens Selys ! 



Black, brassy, beneath yellow ; head black, each side in front 

 slightly tinged with yellow ; prothorax straight posteriorly, tho- 

 rax, with the dorsum black, a yellow humeral stripe, broadly 

 divided, sides yellow, with a broad black stripe above; pectus with 

 a fuscous stripe ; feet black, femora at base and beneath, and tibiae 

 extremely yellowish ; abdomen black, with a steel blue reflection, 

 the last segment having the apical half yellow; appendages black, 

 the superior ones broad, incurved, interiorly excavated, the apex 

 obliquely truncated ; the inferior ones very small, acute ; margin 

 of the valves (9) entire; wings hyaline, apex of the posterior 

 ones entire, pterostigma black, quadrangular, of the posterior 

 wings triangular (<^), apex of the wings with a narrow yellow spot 

 anteriorly, pterostigma absent ( 9 ). 



