328 PERCY SLADEN TRUST EXPEDITION 



Scatella, Robineau-Desvoidy. 



Scatella Robineau-Desvoidy, Essai sur les Myodaires, iii. (1830), p. 801. 



A single species occurs which is characterised by the seven distinct " windows" on the 

 wing. 



31. Scatella septemfenestrata, n. sp. 



Head. Profile like S. stagnalis Fall., but the facial knob is somewhat more prominent. 

 Frons and vertex shining black dusted, two fronto-orbitals ; face dusted with grey pollen, 

 a strong bristle each side above the mouth margin. Back of head and jowls black with 

 grey pollen, a strong bristle on the jowl below the eye. Antennae black. 



Thorax densely covered with red-brown pollen ; when rubbed the ground is seen to 

 be shining black. Scutellum with two terminal bristles and two side hairs. 



Wings as Fig. 17, tinted brownish with seven windows which appear as whitish 

 patches on side illumination, two are between the second and third veins, the distal one 

 being the fainter, three between the third and fourth veins, the distal one being the 

 fainter, the two others lie one each side the cross vein between fourth and fifth. None 

 of these spots are very large nor do they appear to push the veins apart. 



Halters pale whitish yellow. 



Legs entirely black. 



Fig. 17. Scatella septemfenestrata, n. sp., wing. 



Abdomen. Like the thorax with equal segments. 



Size about If mm. 



Locality. Seychelles. Mahe : from marsh just behind beach at Port Glaud, 5. XL 

 1908. 



Canace, Haliday. 



Canace Haliday, Ann. Mag. Nat. Hist., ser. 1, iii. (1839), p. 411. 



One specimen of a new species of this interesting genus was collected on the sea- 

 shore of Mahe. It differs considerably from either of the two European species, being 

 nearer to C. nasica Hal. than to C. ranula. 



32. Canace mahensis, n. sp. (PI. 15, fig. 19). 



The insect is of a uniformly dark grey colour, more silvery on the pleurae and legs 

 and with a silvery face and labrum. 



?. Head. In profile longer than high, while in C. nasica it is the other way, this 

 is partly due to the smaller jowls. There is a well-marked depressed frontal triangle 

 and a large facial knob just touching the base of the antennae. Eyes longish oval, with 

 the major axis nearly horizontal, small. 



