NOVITATBS ZOOLOOICAE XXIII. 1916. 127 



2. Ammalo arravaca spec. nov. (text-figs. 4, 5, 9) 



This species is only known to me from French Guiana and Surinam, all the 

 specimens I have seen from these countries belonging to arravaca. The pair 

 recorded by Lord Rothschild under insulata {Nov. Zool. 1910, p. 35) from " Brazil 

 (Meyer coll.) " is arravaca, and the locality Brazil may safely be regarded as 

 erroneous. 



A. arravaca agrees in colour with insulata, but our specimens are on an average 

 smaller, the forewing measuring from 14 to 16 mm. in length ; this measurement 

 may not be confirmed, if a series larger in number than ours is compared. 



The pectinations of the male antenna are very slightly longer than in insulata. 

 The dorsal processes of the ninth tergite (text-fig. 4, P 1 ) are pointed, tapering from 

 the base to the apex, the slit between them being much wider than in insulata. 

 The valve (V) is practically the same as in that species, but the harpe (H) is 

 strongly curved at the apex, ending iu a sharp point, which often projects beyond 

 the apex of the clasper (text-fig. 5). The tenth tergite is rounded-truncate (x. t.), 

 not pointed as in the other species, and apically flattened. As this organ usually 

 projects from beneath the eighth segment, and can easily be examined, there is no 

 difficulty in distinguishing the <$ of arravaca from the other species. 



The eighth sternite of the female (text-fig. 9) differs from that of insulata in 

 bearing no large median callosity. The apical margin is not incrassate in the centre, 

 or only to a very slight degree. The feeble swelling which is usually present, and 

 which extends forward as an indistinct median ridge, is more due to the segment 

 being slightly folded along the centre than to being actually swollen. If the ridge 

 or fold is distinct, the apical margin of the segment bears a small central notch. 

 This margin is distinctly visible in most specimens without the scaling being 

 touched. If it is concealed the scaling should be lifted up or brushed sideways. 



We have a series of both sexes from St. Jean du Maroni (type 1 ) and St. Laurent 

 du Maroni, French Guiana (E. Le Moult), and Aroewarwa Creek, Maroewym Valley, 

 Surinam (S. M. Klages). The type is labelled September, and Mr. Klages found 

 his specimens in April and May. 



3. Ammalo aurata Butl. (1875) (text-figs. 6, 7, 10) 



The specimens from South-East Brazil are deep buff-yellow, but similarly 

 coloured examples occur also among A. insulata. The deep colouring was the only 

 difference which Butler noted when describing aurata from a single Brazilian 

 female from Espiritu Santo. It was a shot in the dark, but nevertheless a hit. 

 A. aurata occurs on the Lower Amazons and in South-East Brazil. A female in the 

 Tring Museum bears the locality label " La Merced, Chanchamayo." The specimen, 

 however, was not received direct from the collector, and as we have not seen any 

 other specimens of aurata or of insulata from the Andes countries of South America 

 apart from Colombia, the before-mentioned female probably did not come from 

 Peru, but from the eastern side of the continent. I consider aurata a Brazilian 

 species which has extended its range into the Amazon valley (Parä, Manäos), and 

 in the south is found as far west as Tncuman and Paraguay. 



While iu the two previous species about one-third of the frons is blackish, this 

 colour extends in aurata to one-half. This distinction appears to be somewhat 

 more reliable than the difference in the yellow coloration of the wings above 

 referred to. The pectinations of the male antenna are decidedly longer than in the 



