PERLIDES. 145 



Pitchy black: head hardly broader than the thorax, yellow be- 

 neath and at the base of the antennae, and with a yellow triangular 

 spot on the hind-border, which is also yellow : prothorax rugulose, 

 with a yellow middle stripe, not broader in front ; sides straight ; 

 angles rather sharp ; under side yellow : wings very slightly gray ; 

 veins black ; external basilar areolet with six transverse veins ; ter- 

 minal areolet with two transverse veins ; terminal part of the sub- 

 marginal areolet with no transverse veins ; submedian areolet with 

 six transverse veins. Length of the body 4 lines ; of the wings 12 

 lines. 



a. St. Martin's Falls, Albany River, Hudson's Bay. Presented by 

 G. Barnston, Esq. 



13. PERLA MEDIA. 



Niyra ; caput thorace paullo latins, lateribus, margine postico, ma- 

 culisque duabus flavo-ferruymeis ; prothorax valde ruyulosus, 

 antice multo latins, sulco dorsali, anyulis anticis sat acutis, 

 posticis rotundatis ; alls subcinereis. 



Perla media, Barnston, MSS. 



Black : head a little broader than the thorax, ferruginous 

 mixed with yellow on each side and behind, and with two spots of 

 that colour diverging from each other on the vertex towards the 

 fore-border: scutum very rugulose, with a slight middle furrow, 

 much broader in front ; hind-angles rounded ; fore-angles rather 

 sharp : wings very slightly gray ; veins black ; external basilar areo- 

 let with thirteen transverse veins ; terminal areolet with three trans- 

 verse veins ; terminal part of the submarginal areolet with no trans- 

 verse veins ; submedian areolet with eight transverse veins. Length 

 of the body 5 lines ; of the wings 16 lines. 



a. St. Martin's Falls, Albany River, Hudson's Bay. Presented by 

 G. Barnston, Esq. 



14. PERLA NUBES. 



Caput macula flava occipitali ; prothorax omnino niyer, longitudine 

 paullo latins. 



Perla nubes, Pictet, Hist. Nat. Neur. Perl. 174, 9, pi. 9, f. 7, 8. 

 America. 



