436 PERCY SLADEN TRUST EXPEDITION 



of the Libellulinse in connection with the less-known species falling into that Subfamily : 

 he has also devoted much time to the study of the Agriocnemis from the Seychelles. 

 Monsieur Rene Martin, of Paris, has been so good as to identify several other species 

 belonging to a Dragonfly-fauna with which he is so well acquainted. His valuable paper 

 on the "Odonates des lies Sechelles " (M6ra. Soc. Zool. France, ix. pp. 101—112 (1896)) 

 has also been freely consulted. Moreover, frequent use has been made of the monographs 

 by both these specialists which are appearing in the Selysian Catalogue (" Collections 

 Selys "). 



The subjoined list enumerates not only the species collected in 1908 — 1910 in 

 Seychelles, Assiunption, Aldabra, and Cosmoledo, but also such additional species as 

 I have found to be recorded elsewhere from the same islands. It may be added that 

 Dr Philip P. Calvert mentions a male Dragonfly in the United States National Museum 

 collection, from the Seychelles, collected by Dr W. L. Abbott, which may belong to 

 Agvioti insulare Selys (Proc. U. S. Nat. Mus., xviii. p. 142 (1895)). Notices of species not 

 represented in the present collection are enclosed within brackets. No attempt has been 

 made to state the full synonymy of the species discussed, but the original descriptions 

 are always cited, and reference is also made to the Selysian Catalogue in all those cases 

 where the present incomplete state of that great work has permitted of this being done. 



Libellulidse. Libellulinae. 



1. Orthetrum stemmale wrighti (Selys). 



Libdlula wrightii Selys, Ann. and Mag. Nat. Hist. (4), iii. p. 272 (-1869). 



Orthetrum stemmale ivrighti Ris, Coll. Selys, LibelL, fasc. x. p. 219 (1909). 



Loc. Seychelles. Mahe : 5 $ (Dupont) ; 2 ^, Cascade Estate ; 3 $, Long Island, 

 VII. 1908 ; 1 ^, 1 $, taken in coitu, Port Glaud, 5. XL 1908. Silhouette : 8 ^, 4 ?, plateau 

 of Mare aux Cochons, IX. 1908. Bird Island: 1 $ (Fryer), VII. 1908. Dennis Island: 

 1 $ (Fryer), VIIL 1908. Praslin, 1905. Coetivy, 1905. 



The younger males in the series closely resemble the females in the matter of 

 coloration, but when full maturity has been attained the yellow markings on the face, 

 thorax and abdomen are entirely obscured by blue pruinosity ; even the yellow terminal 

 appendages take oh a bi-ight purple colour. One or two aged females also tend to become 

 pruinose. This is the Seychellean form of a species occurring on the Continent of Africa 

 (O. stemmale capense), in Madagascar (0. stemmale lemttr), and in Mauritius and Reunion 

 (O. stemmale stemmale). De Selys {op. cit. p. 273) mentioned wrighti as occurring also in 

 Mauritius, but Ris {loc. cit.) has referred this insect to the typical form, 0. stemmale 

 stemrnale. 



According to Mr Laidlaw's report, a long series of O. wrighti were obtained from 

 the Chagos Archipelago by the Expedition of 1905. No specimens from that locality, 

 however, are now discoverable in the collection, but the data which he quotes are found 

 to apply to a certain number of specimens of Diplacodes trivialis, a species which 

 Laidlaw failed to record at all from Chagos. So far as our knowledge goes, therefore 

 the Seychelles Islands remain the sole habitat of O. stemmale wrighti. 



