LAMB—DIPTERA: HETERONEURIDA, ORTALIDA, TRYPETIDA, SEPSIDA, ETC. 323 
Sepside. 
Sepsis Fallen, Dipt. Suec. Ortal., 20 (1820). 
21. Sepsis rufa Macq., Dipt. Ex., Suppl., iv. (1850), 296. 3; Becker, Mitt. Zool. 
Mus. Berlin, u. (1903), p. 144. 
There is a long range of a variable species which all agree very closely in the 
cheetotaxy of head, thorax, abdomen and legs: they divide roughly into a large pale 
form (typical rufa) and a smaller dark form, but a few intermediates occur. The sole 
difference appears to be that the middle femora in the pale form have three stout bristles 
underneath at middle, while the dark one has only one or two there, and all the bristles 
are weaker in the smaller form. The front femora and tibiz agree with the description 
of Becker (/.c.) and with the description given by de Meijere, Ann. Mus. Nat. Hung., iv. 
(1906), p. 179, and with his figure, /.c. tab. 11, fig. 11. De Meijere in that paper draws 
attention to the same fact, namely that S. rwfa seems very variable in body, leg, and head 
colour, and also in size, which he finds varies from 24 to 4 mm.: in all his specimens he 
also finds the cheetotaxy similar. 
As far as can be seen without detailed dissection, the genitalia are the same in all 
the male specimens. On the whole the females are darker than the males. 
Localities. Seychelles: from a number of localities, both near sea-level and in the 
high mountain-forests. Silhouette: near Mont Pot-i-eau, ca. 1500 feet, VIII. 1908; Mare 
aux Cochons, IX. 1908. Mahé: Cascade Estate, ca. 1000 feet; from near Morne Blanc, 
X.—XI. 1908; Anonyme Island, I. 1909. 
22. Sepsis albopunctata, n. sp. (Plate 19, fig. 11). 
The collection includes three specimens of a male with pale white spots at the tips of 
the wings, and indistinct black spots by them, which do not agree with any of the 
published descriptions. 
Head. Bright shining yellow; on vertex, upper eye-margins, space round each ocellus, 
a broad line below and above, brown orange. Antennz yellow with usual dorsal bristle 
on 2nd joint, and orange arista. Cheetotaxy normal, viz. oc., post-v., inner and outer 
v.; there is a group of bristles each side on back of head between neck and eye-margin, 
and the usual clump just over neck. Three well-marked vibrissze followed by a row of 
equal hairs on the mouth-margin behind them. 
Thorax. Shining orange yellow, pleuree somewhat lighter, a silvery patch on upper 
half of sternopleura. Two d. ¢., the line of these continued to the front by a line of 
bristles, which are much more distinct than usual: acrostichals in two irregular rows 
of the same character as last bristles; other bristles normal. There is a notable dark 
orange line from humeri to wing base along the suture. 
The wings have quite normal venation: 2nd vein slightly turned up at tip, 3rd and 
4th parallel: a terminal white spot (involving the tip of 3rd vein) between 4 and 2, a palish 
dark spot just over the tip of 2, bounded by the pale spot in front, and extending down- 
wards to rds the distance between 2 and 3. The discal cross vein somewhat beyond the 
SECOND SERIES—ZOOLOGY, VOL, XVI. 42 
