Dragonfiies from the Seychelles. 273 



Length of abdomen 24-25 millim., hind wing 27, ptero- 

 stigma 2^. 



<$ adult characterized by the coloration of the front, of 

 which the excavated upper portion is greenish blue, not me- 

 tallic, surrounded with blackish. The upper lip is yellowish, 

 encircled with blackish, and with a median blackish line ; the 

 lower lip yellowish, with the median lobe entirely blackish and, 

 with the inner borders of the lateral lobes, forming a median 

 space of that colour. Abdomen strongly powdered with bluish ; 

 third segment greatly constricted. 



In the ^ non-adult, and in the ? (which was taken by the 

 late M. Julien Desjardins in the island of Mauritius), the tho- 

 rax is not powdered with bluish ; it is blackish, with an ante- 

 humeral band, two lateral ones on each side, and several spots 

 beneath orange-coloured. In the $ the abdomen (which is 

 not pulverulent) has a double median orange-coloured spot on 

 the first to the seventh segments ; the eighth much dilated at 

 the sides. 



3. Libellula trivialis, Ramb. 



One female, which does not differ from Rambur's types in- 

 dicated from Bombay and Macao. A priori I was induced 

 to unite with it the allied species L. flavistyla of Africa, or L. 

 tetra of the Mauritius ; but the number of the " posttrigonal " 

 cells and of the cells in the interior triangle of the superior 

 wings are opposed to this, as well as the form of the abdo- 

 men and of the vulvar scale, which are quite like those of L. 

 trivialis. 



4. Zygonyx (?) luctifera, n. sp. 



$ . Abdomen 32 millim., inferior wing 35, pterostigma 1^. 



Wings hyaline, scarcely tinted ; membranule long, pale 

 brown ; discoidal triangles free, that of the upper wing nar- 

 row, acute at the lower angle, followed by two rows of post- 

 trigonal cellules ; the internal triangle of the superior wings 

 of two cellules, but scarcely to be distinguished from those 

 adjoining ; a single transverse basal nervule in the space 

 between the submedian nervure and the postcosta in all the 

 wings ; the nodus nearer to the apex than the base of the wings ; 

 ten antecubital nervules. in the superior wings, the last iso- 

 lated ; seven to eight in the inferior. Almost entirely coal- 

 black (with steel-blue reflections on the front and fore part of 

 the thorax). Some dull yellowish markings, indistinctly indi- 

 cated, as follows : — a transverse band on the face, comprising the 

 nasus and the rhinarium ; five or six spots on each side of the 

 thorax, and a vestige on the sides of the second abdominal seg- 

 ment. Femora dull brown externally. 



Eyes prominent, somewhat contiguous. Prolhorax with the 



