if 111: sililll hHIhi 'A i • if ' 11 - : ■■:' : II in ill 11 3 . '■■■ ,' y/~ JfH- 2nd Ser. ZOOLOGY.] [Reprinted from VOL. XV. PART 3. THE TRANSACTIONS OF THE L1NNEAN SOCIETY OF LONDON THE PERCY SLADEN TRUST EXPEDITION TO THE INDIAN OCEAN IN 1905, UNDER THE LEADERSHIP OF Mr J. STANLEY GARDINER, M.A. VOLUME IV. No. XIX.— DIPTERA : LONCH^ID^E, SAPROMYZIDiE, EPHYDRID^E, CHLOROPID^E, AGROMYZIDiE. By C. G. Lamb, M.A., B.Sc, Clare College, Cambridge. LONDON: PRINTED FOR THE LINNEAN SOCIETY BY JOHN CLAY, M.A. AT THE UNIVERSITY PRESS, CAMBRIDGE. SOLD AT THE SOCIETY'S APARTMENTS, BURLINGTON HOUSE, PICCADILLY, W., AND BY LONGMANS, GREEN, AND CO., PATERNOSTER-ROW. December 1912. ■ • TJ>31 No. XIX— DIPTERA : LONCH^EID^E, SAPROMYZID.E, EP HYDRIDE, CHLOROPID^E, AGROMYZID.E. By C. G." Lamb, M.A., B.Sc, Clare College, Cambridge. i/' (Plates 15, 16 and Text-Figures 1—33.) (Communicated by Professor J. Stanley Gardiner, F.R.S., F.L.S.) Read 20 June, 1912. Lonchseidse. Lonchcea, Fallen. Lonchcea Fallen, Dipt. Suec, Ortal., (1820), p. 25. 1. Lonchcea splendida Loew, Beschr. Europ. Dipt., iii. p. 292. Several specimens of this fine species were collected. It is known from the Medi- terranean Region. Localities. Seychelles. Bird Island, VII. 1908 (Fryer). Dennis Island, VIII. 1908 (Fryer). Mane" : Cascade Estate, about 800 ft. and over, 1908—9. Praslin : Cotes d'Or Estate, XL 1908. 2. Lonchcea plumata, n. sp. This is a black species with black legs ; the calypters are pale and pale-haired ; there is a long terminal abdominal segment in the $ like that of L. incequalis, Loew. $. The whole insect is uniformly black, including the legs. Head (PI. 15, fig. 1). Frons nearly parallel-sided, slightly narrowing from the vertex to the front fronto-orbital bristle. The vertex and the narrow eye-margins as far as the insertion of the fronto-orbital bristles are very shining. The rest of the frons (including the lower part of the eye-margins) is dull, but the space below the lunule and between the antennal bases is covered with shining dust. The lower eye-margins are black. Labrum just visible in front, antennal fovese shallow but evident. The face widens rapidly from the frons to the mouth. Eyes large, very long-oval in profile, bare. Antennae with second joint somewhat greyish, third joint long and laterally com- pressed, slightly concave in front in side view with a rounded tip, about four times as long as broad, with tip extending almost to the mouth margin. Arista pale and thickened SECOND SERIES— ZOOLOGY, VOL. XV. 39 304 PERCY SLADEN TRUST EXPEDITION at the base, then black ; it is very beautifully feathered, each ray being shaped like an elongated S: there are about 18 rays each side. Palpi stout, fleshy, black and hairy, somewhat compressed sideways. One pair of fronto-orbital bristles, two pairs of verticals, the outer much weaker than the inner, a fine pair of forwardly-directed divergent post- verticals, stout ocellars : in profile the frons is seen to be finely haired all over. Thorax. Dorsum clothed with adpressed hairs, but the hind part is bare. Scutellum duller and greyish in colour. Bristles normal. Wings (Fig. 1) pellucid with yellow veins, the fine costal ciliation black. Calypters small, whitish yellow, pale-margined and white-haired. Halters black with paler stalks. Legs. Front : femora with two rows of long bristly hairs ; tibiae and tarsi clothed with short bristly hairs. Middle : femora all covered with short bristly hairs, an inferior posterior row of longer ones is conspicuous ; tibia? with similar fine bristles and a terminal crown of spines ; tarsi with black bristly hairs. Hind : covered with fine bristly hairs, among which is a somewhat conspicuous row below the femora. i Fig. 1. Lonchcea plumata, n. sp., wing. Abdomen. $. The last segment is slightly longer than the two previous ones together (PL 15, fig. 2) and has the form of a truncate triangle with the end notched. The two angular tips thus formed bear a bunch of black bristly hairs. The whole surface dorsal and ventral is covered with similar hairs which are stouter on the margins of the segments and towards the end of the last segment. $ like the male, except as follows : — Face about one-third as wide again as that of the male ; abdomen with equal segments except the one before the ovipositor, which is a little narrower ; the ovipositor is shining black, acicular, scarcely flattened, the sheath is paler. Size about 4 mm. Localities. Seychelles. Silhouette: Mare aux Cochons, over 1000 ft., IX. 1908. Mahe: Port Victoria, XII. 1908; Long Island, VII. 1908; Anonyme Island, I. 1909; marshy ground near sea-level at Cascade, 20. II. 1909 ; cultivated country about 1000 ft., XL— XII. 1908 ; near Morne Blanc, about 800 ft., X.— XL 1908 ; Cascade Estate, 800—1700 ft. and over, 1908—9 ; forest behind Trois Freres, about 2000 ft., 14. I. 1909 ; Mare aux Cochons district, about 1500 ft., I. — II. 1909. 3. Lonchcea longicornis, n. sp. A shining bluish-black species with red metatarsi, pale calypters with pale hairs. LAMB— DIPTERA : LONCKMIDJE, SAPROMYZID.E, EPHYDRID^, ETC. 305 $. Head (PI. 15, fig. 3). Vertex and ft'ons somewhat shining and slightly hairy ; eye-margins smoother and more shining, especially from the vertex to the fronto-orbital bristles : the front part of the frons and the lower part of frontal eye-margins dull. The upper part of the eye-margins narrows considerably from the vertex to the fronto-orbital bristles. A silvery spot lies between the bases of the antennae. Face with silvery dust and a well-marked narrow central linear keel ; the face widens rapidly from the antennae to the mouth. Antennae close to eyes, so that in front view the antennae are markedly divergent. Eyes bare. Antennae black with the third joint somewhat dusted inside, it is very long and nearly parallel-sided, with an evenly-rounded tip extending in side view well below the mouth margin ; arista long, and microscopically pubescent, brownish at the base, the rest black. One fronto-orbital bristle, fine post-verticals, long ocellars ; frons fine-haired in profile. Palpi fleshy, black and hairy. Thorax. Dorsum bristly-haired, both it and the pleurae are shining black with a distinct blue tinge. Scutellum also shining black but with a faint greenish tinge. Bristles normal. Wings normal : venation much as the last species, but with the lower cross-vein slightly more oblique ; brownish in colour, with yellow-brown veins. Calypters pale with pale borders and hairs. Halters all black. Legs black except that all the tarsi are reddish-yellow. Front : femora with the usual two rows of bristles with some irregular and shorter bristles between ; the upper backwardly-directed row is regular, the lower downwardly-directed row has five or six bristles which are not so long as usual. Middle : femora with a regular row of strong hairs below ; tibiae with only one stout inner bristle of the terminal crown evident. All the legs covered with fine bristly hairs. Abdomen. Ovate in outline with nearly equal segments and a bluntly-pointed tip. From a top view it is seen to be bordered with long fine black bristles ; the outer corners of the second segment with abundant black hairs ; dorsum with longish bristly hairs but no very evident marginal bristles. $. Frons wider than in male, nearly parallel-sided. Ovipositor long black non- flattened with a black sheath ; when fully extended it is nearly as long as the rest of the abdomen. Size about 3 mm. Locality. Seychelles. Mahe" : Cascade Estate, about 1000 ft., 1908 — 9. 4. Lonchcea vibrissifer, n. sp. A black species with yellow metatarsi, calypters pale and pale-haired, and with very long vibrissae. 39—2 306 PERCY SLADEN TRUST EXPEDITION $. Head (PL 15, fig. 4). Frons dull, slightly narrowing from the vertex to the antennae ; in side view it is seen to be bristly-haired ; the bristles on the eye-margins bend backwards, those on the disc of the frons bend forwards, so that in profile the frons appears to be covered with bristles crossing about at right angles. Upper eye-margins which include the vertical and fronto-orbital bristles are bristly, slightly shining and rather short. Face slightly silvery, widening rapidly from antennas to mouth. Jowls very evident, black- haired. Eyes bare. Antennas : third joint black, slightly dusted, short, about twice as long as broad : when looked at from in front the tip of the antenna does not reach the curved mouth margin by about half the length of the third joint. Arista pale at base then black, micro- scopically pubescent. The bristles are normal, the ocellars being stout. There is a prominent stout vibrissa on each side of the mouth. Palpi retracted, brownish black. Fig. 2. Lonchcea vibrissij'er, n. sp., wing. Thorax. Shining black with normal bristles and stout bristly hairs extending nearly up to the prescutellar bristles. Scutellum same colour as thorax. Wings (Fig. 2) brownish in tone with brown-yellow veins. Calypters pale with pale borders and hairs. Halters black with stalks slightly paler in the middle. Legs all black except that the metatarsi and the next joint in the front and middle legs and the next two joints in the hind legs are yellow. The front femora have the inferior row of bristles longer than usual, forming a regular comb. Middle femora with a stout ciliation below and the tibiae with no crown of spines. Abdomen similar to the last species but somewhat more truncate at the tip. $ with a wider frons, the ovipositor short and much flattened, with a pale sheath. Size a little over 3 mm. Localities. Seychelles. Silhouette : plateau of Mare aux Cochons, over 1000 ft., IX. 1908. Mah£: Cascade Estate, about 1000 ft.; Morne Seyehellois, over 1500ft., 4. II. 1909. LAMB— DIPTERA : LONCH^ID^, SAPROMYZIDvE, EPHYDRID^], ETC. 307 Sapromyzidse. Pachycerina, Macquart. Pachycerina Macquart, Suite a Buffon, ii. (1835), p. 511. 5. Pachycerina seychellensis, n. sp. This species must be closely related to P. javana Macq. $. Head (PI. 15, fig. 6). Frons dull yellow orange, paler towards the vertex ; the ocellar spot dull black, nearly circular, but slightly drawn out to the vertex. The two fronto-orbital bristles stand on greyish spots, the spot of the hind one is the larger and is connected to the vertex by a continuing pale greyish line. Face very shining yellow from just above the antennal base to the mouth margin ; it has the usual two roundish black shining spots. Palpi with black heads, the rest yellow. Tongue yellow. Two fronto-orbitals, inner and outer verticals, crossed post-verticals, very fine ocellars between the ocelli, and a very fine pair on the vertical black spot just at the vertex. Hind head bristled on the eye-margins below the outer verticals. A fine row of hairs bordering the cheeks and on the jowls. Antennae yellow ; the first joint pyriform, second cylindrical, bristled at the apex beneath and at the base on top, third very long and gradually tapering to a blunt end ; arista black with very dense stout feathering. Thorax. Dorsum shining, marked longitudinally with brownish and yellowish stripes. Three dorso-central bristles, the last two in the same transverse row as the prescutellar pair of bristles, and two regular rows of achrosticals. The surface has also various scattered hairs ; some of these form well-defined side rows of small bristles, seen best on viewing the thorax sideways ; one such row is a continuation of the dorso-central bristles, another runs roughly parallel to the line of those bristles, but is more remote from the centre line of the dorsum ; this row begins a little before the front dorso-central bristle and ends a little before the third. The yellowish stripes are between the achrostical rows and on the line of the dorso-centrals, and extend to the front of the thorax ; between these three rows are the two bi'ownish stripes. A similar short brownish stripe runs from the intra-humeral bristle to the front of the thorax ; between this and the three post- humeral bristles the humeri and dorsum are again yellow, which colour continues from the side row of bristles over to the hind part of the pleurae. Pleura? yellow with a broad brown stripe extending from the wing base to the front, a similar narrow stripe on the sterno-pleural suture. Scutellum yellow, slightly darkened centrally and at the base, disc somewhat flattened, the usual four strong bristles. Wings normal in venation, yellow but slightly darkened along the costal edge ; veins yellow. Halters yellow. Legs with the usual preapical tibial bristle. Front : femora yellow, brownish on the upper surface with three rows of stout bristles, the underneath row the strongest, tibia? 308 PERCY SLADEN TRUST EXPEDITION black with extreme tip yellowish ; tarsi all black, the last joint with long hairs on the dorsal surface. Middle : all yellow with a crown of two spines on the end of the tibia. Hind : yellow. Abdomen. Shining yellow brown to blackish with a few scattered hairs ; the hind margin of the segments with a row of very long bristles, especially well developed on the third and fourth segments, these marginal bristles extend over the sides. The terminal segments of the $ form a distinct hypopygium of rounded outline, a ventral view of which is given in PI. 15, fig. 5 ; the last segment has a pair of projecting processes with a fine horny process between. Sixth segment with two black dots. ?. The female is similar to the male but has a somewhat pointed abdomen. Size, excluding antennas, 4 mm. Localities. Seychelles. Silhouette: near Mt. Pot-a-eau, about 1500 ft., VIII. 1908 ; Mare aux Cochons, IX. 1908. Mahe : Long Island, VII. 1908 ; marshes on coastal plain, Anse aux Pins and Anse Royale, I. 1909 ; from grass in cultivated country, about 1000 ft., XII. 1908 ; near Morne Blanc, 800 ft., XL 1908 ; Cascade Estate, ca. 1000 ft., 1908—9. 6. Pachycerina obscuripennis, n. sp. In general form and characters this species is much like the last, it is, however, a very dark suffused form. The differences are given below. $■ Head. The ocellar spot is elliptical in outline, extending over the vertex with the hind pair of ocelli standing on its minor axis. The grey line joining the vertex to the upper fronto-orbital bristle is more evident and broader. Antennas : first and second joints dark brown, the second with more hairs, arista more densely haired. Thorax. Dorsum all black brown, the colour extending right up to the scutellum, with a fine yellow line between the achrostical bristles and a yellow border extending from the humeri to round the edge of the scutellum. Wings suffused with black, darkening towards the costa. Halters black. Legs, front femora yellow with a black tip. Abdomen. All shining black with appendages like those of the former species. Size as last species. Locality. Seychelles. Silhouette: forest above Mare aux Cochons, IX. 1908. Sapromyza, Fallen. Sapromyza Fallen, Dipt. Suec, Ortal., (1820), p. 29. Sub-gen. Sapromyza, sens. str. 7. Sapromyza striata, n. sp. This species has the general appearance and the long plumose antennas of the sub-genus Minettia, but it has only one intra-alar bristle visible. LAMB— DIPTERA : LONCH^ID^, SAPROMYZID^E, EPHYDRID^E, ETC. 309 Head (PI. 15, fig. 7). Frons dull, whitish yellow, a slightly darker indistinct stripe extends from the vertex to the base of the antennse. Face white. Back of head yellow behind the vertex, blackish behind the eyes ; below the yellow part are two silvery dots with black bristly hairs on them. Chsetotaxy normal, but the post-verticals long and crossed not merely convergent. Antennse yellow, slightly darkened inside at the tip ; arista brown at base with black flagellum, long haired on the top with about 15 rays, shorter rayed below. Palpi black ; tongue pale. Thorax. Dorsum pale brownish white with two broad brown stripes extending from just above the shoulders over dorsum and over scutellum where they are confluent, so that the scutellum may be said to be brown with whitish sides. Between the two brown dorsal stripes is a whitish stripe, all three being of approximately equal breadth in front. Chaatotaxy normal with three dorso-centrals ; the achrosticals are arranged in eight roughly parallel and ecpiidistant rows of equal sized bristles. Pleurae yellowish white. Wings as Fig. 3 ; spotted, with yellow veins. Halters yellow. Fig. 3. Sapromyza striata, n. sp., wing. Legs all yellow. Front : femora with conspicuous rows of spines on the lower and hind sides. Middle : femora with a row of five spines on the front side at the tip ; tibiae with a crown of spines at the tip. All the legs have the usual covering of small bristly hairs. Abdomen. Yellow, the boundaries of the segments edged with black, the edging of all but the third segment being marginal, that of the third somewhat remote from the margin. A black and slightly interrupted median line runs along the dorsum of the third to the fifth segments joining each transverse black line to the base of the segment. Size, excluding the antennae, 4£ mm. Localities. Seychelles. Silhouette: near Mt. Pot-a-eau, about 1500 ft., VIII. 1908; Mare aux Cochons and forest above, IX. 1908. Mahe : high damp forest between Trois Freres and Morne Seychellois, about 1500—2000 ft., XII. 1908. Praslin : Cotes d'Or Estate, XL 1908. Felicite : forest, XII. 1908. Note. This species must be closely related to Lauxania (Sapromyza) bilineata Speiser, Wiss. Ergebnisse d. Schwed. Zool. Exp. nach dem Kilimandjaro, Dipt. p. 173. The next two species are structurally very similar as regards shape of head, nature of chaetotaxy, size, etc. The principal difference is in the antennae. 310 PERCY SLADEN TRUST EXPEDITION 8. Sapromyza funebricomis, n. sp. Head (PI. 15, fig. 8). Frons dull brownish yellow, eye-margins and ocellar spot somewhat shining. Face whitish yellow, jowls with scattered bristles, vertex bristly along edge from centre round the eye-margins. Antennae with first two joints brownish, third joint black ; arista sub-plumose, black, the basal joint pale. Palpi pale, filiform, with a few long bristles on the lower side. Chaetotaxy normal, post-verticals crossed about half-way ; all the bristles stout. Thorax. Greyish yellow, uniformly covered with tiny bristles ; between the dorso- central rows these form the achrostical bristles which are somewhat irregularly arranged in six rows, the four middle rows being fairly regular and equidistant, the bordering rows more irregular. Chaetotaxy normal with (1 + 2) dorso-centrals, humeral, two post-humeral, one presutural, two supra-alar, one intra-alar, two prescutellar. Scutellum the same colour as the thorax, broadly rounded at the tip. Wings (Fig. 4) slightly tinged with yellow ; veins yellow. Fig. 4. Sapromyza funebricomis, n. sp., wing. Fig. 5. Sapromyza mahensis, n. sp., wing. Halters yellow. Legs all yellow. Front femora with the usual two rows of bristles towards the end on the posterior side, both upper and lower rows have about three bristles ; the interior lower side (where it would be clasped by the tibia if the leg were closed) has a distinct row of tiny bristles on the tip third. Middle femora with a stout row of some five bristles on the distal end of the anterior side, tibiae with a crown of spines. Hind femora evidently ciliated beneath, the ciliation beginning at the middle and getting longer towards the tip. The bristly hairs so commonly present on the ventral parts of the middle and front sterno- pleurae and on the coxae are very well developed. Abdomen. The same colour as the thorax ; margins with stout bristles which extend over to the margin of the succeeding segment. The surface has scattered hairs. The segments diminish slightly in size from the second to the last. In the male there is a slightly swollen hypopygium, but none of the specimens possessed the appendages referred to in the next species. Size, excluding antennae, 3-J mm. Localities. Seychelles. Silhouette : low coconut-planted country near the coast, Pointe Etienne, 17. IX. 1908 ; Mare aux Cochons plateau, one specimen, IX. 1908. LAMB— DIPTERA : LONCH^ID^E, SAPROMYZID^-E, EPHYDRID^E, ETC. 311 Mahe: marshes on coastal plain, Anse aux Pins and Anse Royale, I. 1909; Long Island, VII. 1908 ; Anonyme Island, I. 1909 ; Mare aux Cochons district, 1000—2000 ft., one specimen, I. — II. 1909. All the specimens except two (indicated above) are from near the coast. 9. Sapromyza mahensis, n. sp. This species is very closely allied to the preceding with which it is compared. Head. Form very like last : antennae all pale yellow ; third joint slightly larger ; arista differs as follows : in S. funebricornis the top rays are long at base and diminish to the tip, the lower rays are finer and shorter at the base than at the apex so that the upper and lower rays are of about ecpial length for the distal two-thirds of the arista: in S. mahensis the rays are finer, more distant and on the top are of equal length for about the first two-thirds of the arista ; below they are nearly as long as above, fine and also equally long for the first two-thirds of the arista. The venation (Fig. 5) differs slightly as will be seen from Figs. 4 and 5. The bunches, of hairs on the sterno-pleurae and coxae are less stout. The whole insect is more shining and of a clearer yellow colour. In a few specimens the male genitalia are extruded (PI. 15, figs. 9, 10). These have a median lobe hooked at each side and notched in the middle, two side hooked appendages and a little fleshy hump covered with hairs. In most specimens this is retracted, when the insect has a somewhat swollen knobby hypopygium. Size as last species. Localities. Seychelles. Mahe: Long Island, VII. 1908; Anonyme Island, from grass, etc., I. 1909; marshes on coastal plain, Anse aux Pins and Anse Royale, I. 1909; cultivated country near sea-level at Cascade, II. 1909. 10. Sapromyza nudiuscula, n. sp. Head (PI. 15, fig. 11). Frons and face entirely the same dull bright yellow: clypeus visible in front : mouth margin slightly but sharply produced as seen in profile. Antennae bright yellow, third joint shortish oval, arista brownish but pale at the base and very finely pubescent. Palpi yellow, narrow, with a few fine hairs. Bristles less strong than the last two species. Thorax. Dorsum yellow to brownish yellow covered with fine black bristles (1+2) dorso- centrals : achrosticals in four regular rows with no irregular bordering ones. Chaetotaxy quite normal with smaller and less stout bristles than the preceding two species. Scutellum distinctly flattened on the disc. Wings narrower but with venation like S. mahensis, barely tinged with yellow ; veins pale. Halters yellow. Legs all yellow. Front femora with the usual two rows of bristles behind both very long ; the upper row has six to seven bristles and extends from base to tip of femur, the SECOND SERIES— ZOOLOGY, VOL. XV. 40 312 PERCY SLADEN TRUST EXPEDITION lower row has four bristles, the basal ones being the longer, and also extends all along the femur. Middle tibiae with the terminal crown reduced to one long bristle inside. Hind femora with one or two fine terminal bristles outside, tibia? with one very short stout spine at the end. The coxal and sterno-pleural hair bunches are sparser and shorter than in the last species. Abdomen. Yellow ; surface bristly ; marginal bristles present ; segments of nearly equal length. Size about 3 mm. Localities. Seychelles. Mahe: near Morne Blanc, X. 1908. Silhouette: near Mt. Pot-a-eau, about 1500 ft., VIII. 1908. 11. Sapromyza crassicaput, n. sp. A single specimen was collected of this species, which is at once distinguished by its unusually large head. It has two brown-black spots on the fourth abdominal segment; except for this and the somewhat infuscate front legs, it is entirely yellow. $. Head (PI. 15, fig. 12). The frons is a slightly duller but brighter yellow than the rest of the insect : ocelli reddish. Back of head with regular bristles recalling the post-ocular bristles of the Dolichopicke ; cheeks bristly. Palpi yellow and hairy. The usual two fron to-orbital bristles present, inner and outer verticals, post-verticals somewhat below the vertical margin towards the back of the head and crossed, ocellars more delicate. Antenna? all yellow including the basal joints of the arista, third joint fairly long, aristal flagellum black and slightly pubescent. Thorax. Three dorso-centrals ; the arrangement of the achrosticals is rather difficult to observe as the dorsum is depressed by the pin, they appear to be irregularly six-rowed. Other bristles normal. Wings normal, glassy with yellow veins. Halters yellow. Legs yellow except that the front pair are slightly infuscate, especially on the tibia? and tarsi, and that the middle tarsi are the same. Front femora with the usual row of backwardly-directed bristles above and a row beneath. Abdomen. Finely haired; marginal bristles on all but the middle part of the segments. A large black spot on each side of the fourth segment occupying nearly the whole breadth. Size, excluding the antenna?, 3f mm. Locality. Seychelles. Mahe: Cascade Estate, 800 ft. or more. 12. Sapromyza perpunctata, n. sp. A single specimen was collected belonging to the group with pictured wings. Head (PI. 15, fig. 13). Vertex and frons brown, yellow above the antenna?. The ocelli on a distinct tubercle, fronto-orbital bristles on small black spots. Face brown. LAMB— DIPTERA : LONCHvEID^E, SAPROMYZID^E, EPHYDKIDvE, ETC. 313 Two fronto-orbital bristles, verticals, post-verticals a little below vertex on back of head, ocellars. Antennae: first two joints dark brown, third paler; arista pale with fine pubescence. Thorax. Black-brown variegated with ochreous patches. Dorso-central bristles (1+3) each standing on a black spot in the ochreous patch. Pleurae black-brown with ochreous-grey patches, the bristles standing on small black spots on the grey patches. Scutellurn as thorax with a pale terminal and two side spots. Wings variegated as in Fig. 6 ; darkened between costa and fourth vein, a white spot behind auxiliary vein, three (the middle smallest) between the costa and first vein, two between first and second, two rows of small spots between third and fourth, a spot in front of cross-vein; tip between second and third white. Between the fourth vein and the margin the wing is marked like that of a Tephritid. Halters black. Legs : femora all ringed with two black and two ochreous rings, beginning with a proximal black ring; tibiae yellow with an indistinct ring proximally. Tarsi all yellow. Fig. 6. Sapromyza perpunetata, n. sp., wing. Front femora with the usual backwardly-directed top row of bristles and an underneath row, the latter long. The middle tibiae have a fine terminal spine in addition to the preapical bristle. Abdomen. Brownish-black like the thorax. On each distal and proximal margin is a central triangular pale spot, the proximal ones being the larger ; the apices of these meet in the case of the second segment and nearly meet in the others, hence this row of spots forms an interrupted median line : on the distal margin of each segment there is also a row of pale circular spots three each side on the second segment, two each side on the third, fourth and fifth ; each pale spot has a black central clot from which proceeds a marginal bristle. There are also a few other minute clots near the proximal margin of the segments and on the disc of the same. Size, excluding antennae, 2f mm. Locality. Seychelles. Mahe: Cascade Estate, about 1000 ft., 1909. Sub-gen. Homoneura, De Meijere. Homoneura De Meijere, Tijdschr. voor Entom., li. (1908), p. 142. Three species belong to this sub-genus, but none of them fit in with the cha- racters in the table given by De Meijere (I.e.), nor with any hitherto published descrip- tions. 40—2 314 PERCY SLADEN TRUST EXPEDITION 13. Homoneura varifrons, n. sp. Head (PI. 15, fig. 14). Dull-black behind and forward to before the antennae where the frons is bright orange-yellow: the side stripes on which the fronto-orbital bristles stand are shining brown-black and extend far forward on the frons to the yellow cross- line : the margins between these stripes and the eyes are distinct from the stripes and are dark reddish-brown; the ocellar spot is shining, and a long-pointed frontal triangle extends forward from the spot which is perceptibly more shining than the rest of the central part of the frons though its boundary is not well defined. The face is entirely orange-yellow as are the eye-margins below and the jowls. Antennae : first and second joints dark orange, third with its apical two-thirds blackish, the rest of it dark orange; the degree of darkening is somewhat variable. Arista with the basal joint and first part of second stout, basal joints pale, flagellum black with a black plumosity, which is longest at the base and tapers thence to the tip, the rays below are shorter and of fairly equal length. Palpi darkened orange, especially on the under surface. Tongue orange with fleshy tip. Head bristles normal; a row of fine bristles on the lower eye-margin above the mouth edge; jowls bristly. Fig. 7. Homoneura varifrons, n. sp., wing. Thorax. All completely black, moderately shining; dorsum with a very faint brown pollination, pleura? very slightly shining. Bristles normal, prescutellars rather small, achrosticals in six rows. Pleurae very slightly silvery. Wings (Fig. 7) almost glassy, very slightly tinged with yellow; veins yellow. Halters with dark knobs and yellow stalks. Legs. In the two males the legs are all pale yellow; front femora with the usual two rows of bristles behind, top row with about six equal bristles, lower row three towards the tip succeeded by a ciliation. Middle femora with two bristles at the end which are longer than the other normal bristles, tibiae with a crown of two long bristles as well as the usual preapical one. Hind femora with an evident preapical bristle on the front side. Abdomen. Black with marginal bristles and small ones on the surface. The male genitalia much as PI. 15, figs. 9, 10 but not extruded. The females, in most cases, have slightly darkened middle and hind femora, the darkening extending nearly all over the joints ; the extent of this suffusion varies, and in one case the legs are pale like the male. Size, excluding antennae, about 2f mm. LAMB— DIPTERA : LONCH^LD^, SAPROMYZIDvE, EPHYDRTD^E, ETC. 315 Localities. Seychelles. Silhouette : Mare aux Cochons, over 1000 ft., VIII. — IX. 1908 ; near Mt. Pot-a-eau, about 1500 ft., VIII. 1908. Mahe : Cascade Estate, ca. 1000 ft., 1908 — 9 ; Anonyme Island, from grass, etc., I. 1909. 14. Hbmoneura atra, n. sp. This species is in facies exceedingly like the last. The thorax and abdomen are also completely black, but the slight pollination is practically absent, and the pleurae are not slightly silvery. The differences between the two species are given below. Head. Frons, face and jowls entirely black except for a small brown space just above the antennae and the brownish lower eye-margins. Antenna with the third joint brown, the others black. Palpi black. All the legs are slightly darker orange ; front femora darkened, middle and hind femora quite black. Size as last. Locality. Seychelles, Silhouette: Mare aux Cochons, over 1000 ft., IX. 1908. 15. Homoneura pulchrifrons, n. sp. Head. The central area of the frons is of a very striking deep velvety black ; the side stripes on which the fronto-orbital bristles stand are broad and shining black, they extend right up to the eyes and are joined across the vertex by a narrow shining strip from which the front point of the small shining ocellar triangle projects. The back of the head is also shining black except for a central silvery spot. Face with the top half shining black, the lower half yellow, the broad eye-margins are paler yellow. Below the antennas on each side of the eye-margin is a silvery spot. Jowls yellow. Palpi black, tongue yellow. Antennas entirely velvety black, arista plumose with the longest rays on top at base tapering to the tip, shorter and more uniform in length below. Thorax. Dorsum somewhat shining brownish black, slightly dusted, with the humeral calli and a line from them over the wing bases brownish yellow : sterno-pleuras brown. Scutellum as the thorax but slightly paler round the margin and pale below, the metanotum is yellow. Wings slightly yellow, tinged with brown-yellow veins. Halters yellowish with browner knobs. Legs all yellow : front femora with the usual two rows of bristles, the upper extending nearly to the base with five or six bristles, lower with two distinct bristles on the distal third : middle femora with a distal row of four or five bristles on the front side, tibise with a crown of two spines as well as the preapical bristle ; hind femora with small preapical bristle. Abdomen. Moderately shining black, with marginal bristles and small general bristles. Male hypopygium with a central lobe and two side hooks, the central lobe itself ending in two hooks. 316 PERCY SLADEN TRUST EXPEDITION Size as last species. Localities. Seychelles. Silhouette: from near Mt. Pot-a-eau, about 1500 ft., VIII. 1908 ; Mare aux Cochons aud forest above, IX. 1908. Mahe : from near Morne Blanc, X. 1908; high forest of Morne Blanc and Pilot, XL 1908; Mare aux Cochons district, about 1500 ft., I.— II. 1909. Praslin : Cotes d'Or Estate, XL 1908. Ephydridae. Notiphilinse. ACANTHONOTIPHILA, 11. g. (PI. 15, fig. 23). This genus comes near Notiphila, Fallen. Head. Eyes longish oval with the major axis vertical and the radius of curvature greater at top than bottom. Jowls present. Face and frons broad, nearly parallel-sided, in profile somewhat hollowed beneath antennae. Hind head somewhat protuberant. Vibrissa? present. Prelabrum visible. Bristles ; inner and outer verticals, two upper fronto-orbitals (bent outward), two lower (bent forward) ; divergent ocellars ; fine post-verticals, two pairs of stout bristles on the frons. Antenna as in Notiphila ; the second joint bristly with a very stout terminal spine; the arista with few rays (three in the typical species). Fig. 8. Acanthonotiphila coriacea, n. g. et u. sp., wing. Thorax and scutellum covered with stout bristly hairs, which are arranged in moderately regular rows ; they are similar in character all over the dorsum so that there is no distinction between the achrostical and the other rows. A pair of prescutellars but no definitely assignable dorso-centrals : one humeral, one intra-humeral, two noto-pleural, two supra-alar, four scutellar (the terminal pair crossed at the tips), two meso-pleural, one sterno-pleural. Wings (Fig. 8), costa to third vein but also rather thickened between third and fourth veins, bristly to the first, the last bristle being longer and like a small spine ; third vein with three or four bristles on the dorsal side, where it is met by the second vein. Abdomen with segments of nearly equal length. The texture of the insect is coriaceous. Type, the following species. 16. Acanthonotiphila coriacea, n. sp. (PL 15, fig. 23). Head. Frons darkish grey, the bristles standing on minute black spots ; the frontal triangle is marked out by two rows of slightly converging fine hairs which begin from the LAMB— DIPTERA : LONCH^ID^E, SAPROMYZIDJE, EPHYDRIDiE, ETC. 317 inner vertical bristles. Inside the triangle stand the ocellar bristles, two smaller slightly convergent bristles just beyond the front ocellus, and two stout parallel bristles nearly in a line with, but proximate to, the line joining the front pair of fronto-orbitals. There are a few hairs in the space between the frontal triangle, the eyes and the last fronto-orbital bristle. Face slightly widening to the mouth, somewhat silvery, the prelabrum yellowish on its margin. Jowls about one-fifth the vertical height of the eyes. Two vibrissa on each side and a bristle on the jowl below the eye. Back of head the same colour as the frons. Antennas with first and second joints yellow, third joint brown. Arista with three side and one terminal rays. Palpi yellow with a few stout black hairs below ; tongue rather horny. Thorax. Olivaceous with minute granular pollination ; chaetotaxy as in generic description ; scutellum darker but paler at the tip ; pleurae dark grey, slightly shining, hairy on the meso-pleura and about seven hairs on the sterno-pleura, three in a horizontal row at the top and four in a vertical row from the mid-point. Metanotum somewhat shining, silvery grey. Wings glassy with yellow veins, costa ciliated with fine closely-packed black hairs, stouter on the first section. Halters pale. Legs. Coxae yellow ; femora all dark brown-grey except the knees ; tibiae suffused ; tarsi yellow except the last joint in hind and middle and last two joints in front legs. All the legs clothed with short bristly hairs ; a longer row below the front femora ; a stout spine at the end of the middle tibiae. The hairs on the tarsal joints are exceptionally evident. Abdomen. Shining brown-black, the last segment being the darkest ; the distal margins of the segments are very narrowly lined with a paler tone. Dorsum covered with bristly hairs, the marginal ones longer : the last segment has some eight still longer bristles, which stand out more nearly perpendicular to the sm-face. Size. 2^ mm. Locality. Seychelles. Mahe : from seaweed on beach at Anonyme Island, I. 1909. Paralimna, Loew. Paralimna Loew, Monograph of the Diptera of N. America, i. (1862), p. 138. 17. Paralimna lineata De Meijere, Tijdschr. voor Entom., li. (1908), p. 165. This species was described from Semarang : the specimens from the Seychelles agree closely with the description. Localities. Seychelles. Mahe : from marshy ground just behind the beach at Port Glaud, 5. XL 1908 ; marshy ground near sea-level at Cascade, 20. II. 1909. 318 PERCY SLADEN TRUST EXPEDITION Hecamede, Haliday. Hecamede Haliday, Ann. Mag. Nat. Hist., ser. 1, iii. (1839), p. 224. 18. Hecamede lacteipennis, n. sp. This is a very distinct and brightly-coloured species. Head (PI. 15, fig. 15). Frons with a large grey triangle extending to the lunula, eye-margin grey, the rest of frons orange-yellow : this colour thus forms two triangles pointing backwards from the front margin : the lunula is whiter. The bristles are as follows : inner and outer verticals, a pair of bristles just behind the line joining the hind ocelli, two other pairs near the margin of the triangle, the pair nearer the back of the head being about half-way down the triangle, the other pair half-way between the former pair and the point of the triangle ; in addition the triangle has some dozen bristly hairs of which two form a distinct pair just at the tip of the frontal triangle. There are two pairs of fronto-orbital bristles, the front pair bent forwards, the other backwards. The face is silvery white with a distinct suture running up each side to meet the margins of the lunula : just along the side of this suture is a row of three vibrissa?, the top ones standing on a very small hillock ; the facial knob is small, shining and very prominent. Fig. 9. Hecamede lacteipennis, n. sp., wing. The jowls are shining silvery and have only one or two fine bristles instead of the many bristles of H. albicans ; the tongue is reddish-yellow with its bent tip only about half the length of that of the latter species. The palpi are pale yellow. Antennae as in H. albicans, with pale yellow second joint and slightly darkened third joint ; arista short with four side and one terminal rays. Thorax. Similar in form to H. albicans but is pale grey in colour like the abdomen of that species ; its surface and that of the concolorous scutellum is uniformly covered with short stout bristly hairs ; chsetotaxy normal including the six scutellar bristles. Wings as Fig. 9, white, with perfectly pale veins. Halters yellow. Legs yellow except the femora which are rather dark silvery grey ; the last tarsal joint somewhat suffused. LAMB— DIPTERA : LO^GHJEIDJE, SAPROMYZID^E, EPHYDRIDiE, ETC. 319 Abdomen concolorous with thorax, except that the base is often slightly reddish ; dorsum with sparse scattered bristles, those on the last two segments being longer. Size. 2 to 2^ mm. Localities. Astove Island : 1907 (Thomasset). Coetivy: 24. IX. 1905. Seychelles: Mahe, from seaweed on beach at Long Island, VII. 1908. Mosillus, Latreille. Mosillus Latreille, Hist. Nat. Ins. et Crust., xiv. (1804), p. 389. 19. Mosillus albi-pennis Loew, Stettin. Ent. Zeit., viii. (1848), p. 14. This species is recorded from S. Europe, Egypt and Teneriffe. The Cambridge Collection contains several specimens from Durban, Natal. Locality. Seychelles. Mahe: one specimen from Anonyme Island, I. 1909. Enchastes, n. g. (PI. 15, fig. 21). A single specimen (in excellent condition) of a new genus near Mosillus was in the collection ; though but a single specimen is available it is thought best to give a full description of the proposed genus, as the insect is of considerable interest. The genus Mosillus was long considered to be in the Chloropidse, but was finally placed among the Ephydridse from the presence of certain structural details, although the general facies is very strongly that of a black Chloropid. The present insect is similar to Mosillus in many important respects but is more Ephydrid in form and is of a dull green surface which is slightly shagreened, recalling the texture of Pelina. Head. Eyes bare, long, oval with axis vertical ; jowls deep. Antennae with rounded third joint, which is but little larger than the second ; the basal bristle on the second joint is minute though evident. The top fronto-orbital bristles are small and in line with the front ocellus, the other fronto-orbitals are reduced to hairs. Small inner verticals and a pair on the frons just beyond the front ocellus. The most striking difference between Mosillus and Enchastes is best seen on a front view (PI. 15, fig. 22). In Mosillus the sutures extending from the ends of the lunule each side and separating the face from the cheeks are very nearly parallel ; the eyes are round ; hence the cheeks widen greatly from the antennal level downwards. In the present genus these sutures diverge somewhat ; the eyes are long-oval and hence the cheeks are much more nearly of constant breadth from the antennal level downwards. The face is protuberant and has a large oblong shining knob : the four facial bristles stand on extremely minute hillocks. The prelabrum is very protuberant and is rect- angular or spade-like in profile. Thorax and scutellum, dorsum with the surface minutely granulate and covered with short bristly hairs instead of the fine hairs of Mosillus. The last pair of dorso- central bristles, a single notopleural bristle just before the wing base, two mesopleural which are not very strong, two scutellars crossed at the tip. The scutellum is rounded at the tip. Wings and legs much as in Mosillus. Type, the following species. SECOND SERIES— ZOOLOGY, VOL. XV. 41 320 PERCY SLADEN TRUST EXPEDITION 20. Enchastes scotti, n. sp. (PL 15, fig. 21). Head (PI. 15, fig. 22). Form etc. as described and figured for the genus; frons dull dark grey, a frontal triangle is demarcated by two rows of tiny bristles. Eye-margins narrow and more silvery. Antennae orange red. Face shining grey with four bristles each side pointing to the centre line and a few other scattered ones; facial knob extremely shining. Jowls and back of head rather silvery. Prelabrum horny, shining with silvery sides and central spot ; tongue coriace- ous, the palpi are hidden. Thorax and scutellum blackish with a fine faintly greenish granulation and black bristles. Wings with venation as figured with third and fourth veins convergent at the end ; veins pale. Halters orange. Legs : femora and tibiae dark black-grey with orange knees and tarsi except the last joint. The middle femora with stronger bristles in front. Abdomen shining black-grey slightly suffused with reddish at the base ; second, third and fourth segments increasing progressively in breadth, fifth pointed, pollinated and more hairy than the others. Size. Just under 3 mm. Locality. Seychelles. Mahe : from seaweed on beach at Anonyme Island, I. 1909. Discomyza, Meigen. Discomyza Meigen, System. Beschr., vi. (1830), p. 76. 21. Discomyza similis, n. sp. This species is allied to the Palaearctic D. incurva Meigen, from which it differs in many points but most markedly in the breadth relative to the length. It is about as long as D. incurva but is proportionately more slender than that insect ; the ratio of maximum thoracic breadth to length measured from the scutellar junction to the front margin is slightly greater than lj in D. incurva,, while in the new species the ratio is about unity : this ratio holds approximately also for the head and abdomen. The following description is based principally on the differences between D. similis and D. incurva. Head. The frontal triangle is proportionately larger and is somewhat wrinkled or rugose instead of being flat and shining. The face is similarly knobbed on each side below the antennae, but just below these there are from six to eight small circular pits instead of a shining triangle. Antenna black, the third joint slightly suffused with grey instead of the second joint being extensively bright red, the arista is six-rayed : the chaetotaxy is the same, but the bristles are longer and less stout. Correlated with the greater ratio of length to breadth the face is more rounded in outline. LAMB— DIPTERA : LONCHjEID^, SAPROMYZID^E, EPHYDRID^E, ETC. 321 Thorax slightly greyer in tone with the scutellum more pointed, and not abruptly cut across. Wings, as Fig. 10, with blackened costa. Halters pale yellow. Legs the same, front pair all black, middle and hind black except for the bright red first to fourth joints to the tarsi. Size. Most specimens are from 3 to 31 mm., but one measures only 2^ mm. Localities. Seychelles. Mahe : from marsh just behind beach at Port Glaud, 5. XL 1908 ; Anonyme Island, I. 1909 ; marshy ground near sea-level at Cascade, 20. II. 1909 ; marshes on coastal plain, Anse aux Pins and Anse Royale, I. 1909. Ilythea, Haliday. Rythea Haliday, Ann. Mag. Nat. Hist., ser. 1, iii. (1839), p. 408. Two species of this interesting genus were collected, but unfortunately the specimens were not in first-rate condition so that very full descriptions cannot be given. Fig. 10. Discomyza similis, n. sp., wing. Fig. 11. Ilythea fraclivirgata, n. sp., wing. 22. Ilythea fractivirgata, n. sp. Head. Profile very like I. spilota Curtis, except that the back of the head behind and below the eyes is not quite so swollen. Chsetotaxy the same but the bristles less strong. Antennae similar, but the third joint slightly smaller and the five aristal rays propor- tionately longer. In top view the head is not quite so flattened, and in front view the shining elongate central knob does not extend so far down to the mouth-margin. The frons is shining, while the face, jowls and lower eye-margins are dusted with grey. The palpi are long, thin and pale with a few bristles near the end ; tongue yellow with a bent-back tip. Thorax. Dorsum and scutellum shining blue-black, slightly dusted : as far as can be seen the chastotaxy is normal, but the bristles are again proportionately weaker. Wings as in Fig. 11, with remarkable interrupted blackish transverse bands, three in number. Halters yellow. Legs all yellow. 41—2 322 PERCY SLADEK TRUST EXPEDITION Abdomen black and shining, otherwise like that of /. spilota. Size. \\ mm. Locality. Seychelles. Mahe : from marshy ground near sea-level at Cascade, 20. II. 1909. 23. llyihea invenata, n. sp. This species is very close to the last as regards its main characters. The characters of head, thorax, etc. are practically the same, the principal difference being the reddish colour of the facial dusting, the longer scutellar bristles, the more orange-yellow legs with the front coxae nearly black. Wings (Fig. 12). These offer a very striking peculiarity inasmuch as the cross veins are absent : the picture on the wings is more like that of the typical species. Four specimens of this new species are in the Cambridge Collection and were sent by Mr F. Muir from Durban. Size about l\ mm. Locality. Seychelles. Mahe : marshes on coastal plain, Anse aux Pins and Anse Royale, I. 1909. Fig. 1 2. Ilythea invenata, n. sp., wing. Fio-. 13. Psilopa nitidissima, n. sp., wing. Psilopa, Fallen. Psilopa Fallen, Dipt. Suec., Hydromyz., (1823), p. 7. 24. Psilopa nitidissima, n. sp. This species is very closely related to the Palaearctic species P. compta Meigen ; it is however much more shining, being brilliant green with coppery or purplish reflections instead of pure green. In the description given comparison is made with P. compta. Head similar in form, chtetotaxy etc. including the antennae, except for being brilliantly shining. / Thorax. Similar ; scutellum more swollen at the sides, the flattened part of disc smaller, and the whole somewhat smaller in proportion and more rounded in outline. Wings (Fig. 13) differ in that the second vein is shorter. Legs ; differ in that the tibiae are all blackened in the middle. Abdomen, very shining, the distal part is red-coppery in colour. Size. 2 mm. Locality. Seychelles. Mahe" : from marshes on coastal plain, Anse aux Pins and Anse Royale, I. 1909. LAMB— DIPTERA : LONCHiEIDJE, SAPROMYZIDiE, EPHYDRIDtE, ETC. 323 25. Psilopa longicornis, n. sp. This species is rather aberrant in the genus, but seems best placed there. It is an elongate form with an exceptionally long third antennal joint. Most of the specimens were rather worn, so that slight uncertainty arises in regard to the colours. Head (PI. 15, fig. 16). Frons and vertex greenish brassy with grey pollination, the broad eye-margins more brassy but not truly shining : a well-marked straight lunular suture crosses the frons just above the antenna and extends from one eye-margin to the other. Below this the face is pollinated like the frons. The pollination is frequently rubbed off, when the ground colour beneath is seen to be reddish bronze. Jowls silvery ; prelabrum often showing slightly, shiny, and horny in texture. Inside of mouth and the palpi yellow; tongue stout and yellowish grey. The usual pair of fronto-orbital bristles inserted side by side, strong, the inner pointing backwards the outer forwards; inner and outer verticals ; very long ocellars ; stout vibrissas, and the usual stout long bristle on the hind head just below the back of the eye. Antennae blackish with yellow tone, the basal joints being somewhat silvery ; the curved bristle on the second joint is fairly long but fine ; third joint very long, arista long pectinate with eight side rays and one terminal. Fig. 14. Psilopa lonyicomis, n. sp., wing. Thorax. Shining greenish with grey pollination ; a well-marked more brassy central line, each side of this being well pollinated. The dusting is easily knocked off, and many specimens were bare. One pair of dorso-central bristles, scutellum dusted like the thorax, a pair of terminal bristles and the usual pair near the base are especially long and stout. Wings (Fig. 14); veins yellow. Halters, knob whitish and stalk yellow. Legs yellow with very slightly darkened femora. Abdomen, dark greenish black, slightly pollinated with the basal part of the dorsum often yellowish in the centre ; the whole is covered with stout bristly hairs, longer on the margins of the segments. Size about 2 mm. Localities. Seychelles. Mahe : marsh just behind beach at Port Glaud, 5. XI. 1908 ; marshes on coastal plain, Anse aux Pins and Anse Royale, I. 1909. 324 PERCY SLADEN TRUST EXPEDITION Allotrichoma, Becker. Allotrichoma Becker, Dipterolog. Studien, iv., Berlin. Ent. Zeitschr., xl. (1895), p. 121. Some 14 specimens of an insect were collected which seems to be best placed in this genus. The male agrees with Becker's generic characters and possesses peculiar genitalia like those figured by him (I.e., Plate IV, figs. 7, 8). The female is extremely like a Disco- cerina and in both sexes the form and colour bear a strong resemblance to those of a member of that genus. 26. Allotrichoma argentiprcetexta, n. sp. Shining black like a Discocerina, covered with fine sparse golden pollination. Head (PI. 15, fig. 20). Vertex and frons shining black, no well-marked frontal triangle, in good specimens the pollination is evident. Face rather silvery, with a well- marked silvery line above the mouth extending round the lower eye-margin ; prelabrum exserted, shining blackish. Antennae black, arista thickened at the base with four side rays, shortening from the base to the tip, and one terminal ray ; a well-marked bristle on the second joint. Fig. 15. Allotrichoma argentijyrcetexta, n. sp., wing. Face with two well-marked side bristles; the usual chsetotaxy, backward and forward orbital pair, ocellars, inner and outer verticals, strong forwardly directed post-verticals as strong as the ocellars. Thorax with fine achrostical and other similar fine bristles each side of them on the dorsum. Scutellum rounded and slightly arched with four bristles. Wings as Fig. 15 with dark veins. Halters white. Legs dark brown with the first joints of the tarsi light brownish yellow, last joints slightly suffused. Abdomen $. Third segment about twice as long as the second ; fourth pointed, nearly as long as the previous two ; fifth very tiny or drawn beneath. Hypopygium with appendages shaped like small pale flattened strips of nearly uniform width, not spatulate as shown in Becker's paper (I.e. Plate IV, fig. 7), two stout divergent hairs on the end and a finer central hah, and a few various sized hairs along the side. ?. Five segments visible, each a little longer than the previous, the fourth greater than third and third greater than second; rounded visible fifth segment, abdomen covered with fine hairs. LAMB— DIPTERA : LONCH^EID.ffi, SAPROMYZID^E, EPHYDRID^E, ETC. 325 Size (excluding antennae) about 1^ mm. Localities. Seychelles. Silhouette : low coconut-planted country near the coast, Pointe Etienne, 17. IX. 1908. Mahe : marshes on coastal plain, Anse aux Pins and Anse Royale, I. 1909 ; near Morne Blanc, about 800 ft., X — XL 1908 ; Cascade Estate, about 1000 ft., 1908—9 ; Anonyme Island, I. 1909. Hydrellinse. Hydrellia, Robineau-Desvoidy. Hydrellia Robineau-Desvoidy, Essai sur les Myodaires, v. (1830), p. 790. A single species of this genus was found which Mr J. E. Collin informs me belongs to the griseola group. 27. Hydrellia varices, n. sp. A black insect with variegated legs. Head. Frons, vertex and back of head black, rather shining, slightly brassy. A bright silver lunule over the antennae. Face closely covered with shining brown-gold pollination with four well-marked fine bristles bordering the eyes. Jowls small, grey as is the lower back of the head, two bristles just below the back lower angle of the eye and a few scattered ones behind it. Palpi yellow, antennse black with nine side rays and one terminal. Thorax, shining black with greenish tone : two pairs of dorso-centrals, the front pair very near the cross suture, continued forward by a few small bristles. Achrostical bristles in two rows, fine. Scutellum as thorax, flattened on the disc, two terminal and two basal bristles with two fine side hairs between. Pleurae and metanotum grey. Wings normal in venation with brown veins. Halters, bright yellow knobs with somewhat darkened stalks. Legs : front, coxae yellow but slightly darkened at the base in front ; trochanters yellow; femora black with extreme tips (at each end) yellow ; metatarsus yellowish, other tarsal joints black but just perceptibly spotted with yellow at the extreme distal tip. Other legs as front but coxae and trochanters slightly suffused and the hind metatarsi brighter yellow. Abdomen; black, less shining than thorax, bristly, the marginal bristles being especially distinct ; segments of nearly equal length. Size about If mm. Localities. Seychelles. Mahe : marshes on coastal plain, Anse aux Pins and Anse Royale, I. 1909 ; cultivated and marshy country near sea-level at Cascade, 20. II. 1909 ; cultivated country about 1000 ft., XI — XII. 1908; near Morne Blanc, about 800 ft., X— XL 1908. 326 PERCY SLADEN TRUST EXPEDITION Philygria, Stenhammar. Philygria Stenhammar, Ephydr., (1844), p. 238. 28. Philygria striata, n. sp. A single specimen was captured which is superficially much like a small P. picta Fall., with which the species is compared in the description. It has the same two silver thoracic stripes and silvery eye- margins. The differences are as follows : Head. The third joint is much smaller, pointed, a little longer than broad, slightly hairy at the top ; the aristal rays are much finer and less regular and pale instead of black; the first two-fifths of the arista is very thick and then suddenly thins out for the remainder. The mouth is less prominent ; the lower eye-margins are proportionately a little wider. Two vertical bristles and the ocellars present but finer. Thorax. The silvery stripes are a little wider, and the dorsum of the scutellum is the same colour as the disc of the thorax, not deep dull black : the silvery side spots to the scutellum are present. Wings ; the second vein is longer and all the veins thinner and paler. Halters like picta with long whitish heads. Legs entirely pale yellow with no infuscation. Abdomen the same, but the anal half is not quite so shiny and the third segment bears two small dusty spots. Size. 1 mm. Locality. Seychelles. Mahe : marshes on coastal plain, Anse aux Pins and Anse Royale, I. 1909. 29. Philygria sp. ? There are two imperfect specimens gummed on card which belong to the picta group. It is impossible to give any description owing to the condition of the specimens. Locality. Seychelles. Mahe : marshes on coastal plain, Anse aux Pins and Anse Eoyale, I. 1909. Ephydrinse. Parydra, Stenhammar. Parydra Stenhammar, Ephydr., (1844), p. 144. The single species of this genus is somewhat aberrant in that it has a pointed antenna and teeth on the front femora; in appearance it is nearer to P. pusilla Meig., than to the other more normal members of the genus. 30. Parydra tuber cul if era, n. sjd. Head (PI. 15, fig. 18). Frons, vertex and back of head shining black obscured with yellow pollination on the back, slightly so on the eye-margin and above the antennae. In LAMB— DIPTERA : LONCH^EIDiE, SAPROMYZIDyE, EPHYDRIBvE, ETC. 327 top view the head is mainly of excessively shining black which forms an area bounded forwardly by the pollination over the antennae and sideways by the eye-margins, but extending in a triangular shape from the vertex almost down to the neck where the boundaries are formed by two elongate excessively pollinated patches. The ocelli are nearly in the centre of this shining area. The face and jowls are also shining black with a neatly distributed sparse white pollination ; in front view this invades the frons above the antennae. Hind head swollen as are the eye-margins except just at the centre of the hind margin of the orbits. The sides of the head behind are also well pollinated. Tongue with dark grey chitinous basal part clothed below with fine white silky hairs, the distal part horny, the tip with a few small teeth. Palpi linear, yellow. Antennas black, the arista thick for the first two-fifths, of the next portion the proximal half is finely pubescent on the top and the distal half is bare ; third joint oval with a remarkable pointed tip. Chsetotaxy normal ; two fronto-orbital bristles, ocellars, inner and outer verticals ; a fine but long bristle projects from each side of the facial eye-orbit and is succeeded by side rows of eight to ten fine hairs along the lower eye-margins ; the projecting prelabrum is the same colour as the face. Fig. 16. Parydra tuberculi/era, n. sp., wing. Thorax and scutellum shining black with a very neat sparse yellow pollen, two shining patches over the wings and each side of the base of the scutellum. One pair of dorso-central bristles, other bristles normal but the achrosticals very fine and indistinct ; pleura grey owing to pollination. Wings as Fig. 16, finely ciliated all round the margin, thicker on the first costal segment; veins brown; no paler or transparent "windows" or patches present. Halters orange. Legs bright orange yellow, except the last tarsal joints which are black and finely haired, the hairs being stronger on the hind tarsi and on the last joint of the other tarsi. Front femora with a row of tubercles starting at the centre (PI. 15, fig. 17), where the femur is thickened, and forming a row of blunt saw-teeth from there up to the insertion of the tibia ; between the tubercles are fine hairs ; middle femora ciliated below. Abdomen. Shining black with sparse pollination ; the margins of the segments paler, yellowish and less shining. Size about 2 mm. Locality. Seychelles. Mahe : marshy ground near sea-level at Cascade, 20. II. 1909. SECOND SERIES— ZOOLOGY, VOL. XV. 42 328 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. LAMB— DIPTERA : LONCHyEID^E, SAPROMYZIDJE, EPHYDRIDvE, ETC. 329 The bristles are as follows: three stout outwardly overhanging fronto-orbital bristles, inner converging verticals and outer somewhat finer verticals, no true post-verticals ; an ocellar pair midway between each basal ocellus and the front one; another pah of bristles in front of these, each about midway between the true ocellar bristles and the forward fronto- -^ orbital bristles. The ocelli are unusually wide apart and form an equilateral triangle. The silvery jowl bears three bristles about equally spaced, the lowest is below about the middle of the eye and half-way down the jowl, and points downwards and forwards, the other hind two point somewhat upwards; on viewing the face in profile the fronto- orbital and jowl bristles converge towards one another to form a sort of cage to protect the eyes. The facial bristle of C. nasica is absent. The antennas are much as in that species, black, with a faintly pubescent arista. The silvery labrum is visible; tongue large and fleshy. Thorax. The chsetotaxy is as in C. nasica, but the four dorso-central bristles and the marginal bristles are proportionately longer and more striking. Otherwise the dorsum is absolutely bare and smooth, contrasting with the bristly dorsum of C. nasica. The scutellum has four bristles, the terminal ones directed upwards, the two basal ones backwards, but it lacks the small dorsal pairs. The pleural bristles are destroyed by the pinning of the specimen. Wings and halters as C. nasica. Legs : front femora have a row of five fine long bristles, and the middle and hind femora are slightly spiny in front; hind femora in no way thickened. Abdomen. Narrow and long but segmented as in C. nasica ; two processes on the dorsal side for holding the egg as shown in the figure. The preceding segment has the pair of long bristles. Size about If mm. Locality. Seychelles. Mahe: from seaweed on beach at Long Island, VII. 1908. A second badly preserved specimen is among some material from Coetivy. Chloropidae. Chloropinae. Ops, Becker.* Ops Becker, Ann. Mus. Nat. Hung., viii. (1910), p. 402. 33. Ops glaberrima, n. sp. (PL 16, figs. 1 — 4). $, ?. This species must be near Chloropisca callichroma Loew from Africa, but differs therefrom in several essential points. Head (PI. 16, figs. 1, 2). The frons and face are of equal width, the eye-margins being parallel and equidistant from the vertex to the mouth. The vertex and frons are bright yellow with a small black shining vertical spot. The vertical "triangle" (PI. 16, fig. 2) is very shining and extends from the vertex (where it nearly fills the space from * This name is preoccupied in the Lycaenidae ; see de Niceville, Journ. Bombay Nat. Hist. Soc, vol. ix. 1895, p. 296. 42 2 330 PERCY SLADEN TRUST EXPEDITION eye to eye) to close up to the base of the antennae: the front edge terminates in a slightly curved line which covers one-third of the frontal breadth ; the side margins are slightly concave. Note. When the specimen is shrivelled the shape of the frons etc. has a somewhat different appearance: the central strip of the frons is more strongly chitinized than the spaces between it and the eyes; on drying this central strip falls in and drags the side strips down with it so that the frons appears to be deeply furrowed; the bottom of the furrow being the central strip, the side strips now form roughly perpendicular boundaries of the furrow. When this occurs the eye-margins no longer appear parallel throughout. The face is yellow slightly dusted with silver, with two very shallow antennal fovese: the mouth opening when viewed perpendicularly to its plane is trapezoidal in outline; the upper lip is pale, the sides of the mouth edge are margined with a fine brown line ; palpi and tongue reddish brown. Antennae reddish yellow with a brown slightly pubescent arista. Back of head black with a broad yellow margin all round; jowls very small. Thorax (PI. 16, fig. 3). Dorsum shining black with a somewhat irregular contour, having a nick at the cross suture, and a slightly wavy and less sharply defined hind margin. The black central part is bordered with bright yellow; pleura yellow with a reddish linear spot just behind the cross suture and an elongated black spot on the same. Fig. 18. Ops glaberrima, n. sp., wing. Scutellurn in the form of a nearly equilateral triangle with rounded angles: very flattened on the dorsum; a pair of short black converging terminal bristles; metanotum shining black. Wings (Fig. 18): venation normal, the distal part of the fourth vein being much less distinct than the other veins ; extreme base of costa blackish and slightly swollen. Halters with bright canary yellow knobs, stalks blackened beneath. Legs pale yellow including the tarsi, which have minute black claws. Abdomen. First and second segments reddish yellow, the latter with the usual two tiny black spots on the extreme margin, sides paler. The third shining black including the sides to the belly. Fourth yellowish with a broad black stripe interrupted in the centre, the breadth of stripe and interruption varying somewhat in different specimens. Fifth yellow with two elongate black basal side spots, the remainder being pale yellow. Size. 2 to 2^ mm. LAMB— DIPTERA : LONCHiEID^E, SAPROMYZID-ffi, EPHYDRID^], ETC. 331 Localities. Seychelles. Mahe: Cascade Estate, about 800 ft., 1909; near Morne Blanc, X. — XI. 1908; swept from rank vegetation in marshes on coastal plain at Anse Eoyale, I. 1909. Var. dentata, n. var. A pale variety (or sub-species) occurs in which the thoracic black dorsal mark extends less far behind and appears like a central mark with two backwardly directed side lobes (PI. 16, fig. 4). The abdomen is wholly devoid of black marks, the basal part being reddish yellow, the rest pale yellow. Localities. Seychelles. Mahe: Cascade Estate, about 800 ft., 1909; marshes on coastal plain, Anse Royale, I. 1909. Oscininee. Gampsocera, Schiner. Gampsocera Schiner, Wien. Ent. Monatschr., vi. (1862), p. 431. A single specimen of an insect was obtained which seems best placed in this genus. The specimen agrees with Schiner's generic characters with the exception of the shape of the scutellum : Schiner's description says, " Ruckenschild flach gewolbt, am Rande beborstet, Schildchen verhaltnissmassig klein." Becker (Archivum Zoologicum, Vol. i. no. 10, p. 117) defines the genus and figures the head of G. scutellata Heeger; he describes the scutellum as " halbkreisformig. " The present specimen agrees with his figure as to the shape of the head and antennae, but the scutellum is elongate as shown in PL 16, fig. 5. In other respects the agreement with the published generic character is close. 34. Gcunpsocera scutellata, n. sp. $. Head. The shape is very like Becker's figure {I.e. Plate III, fig. 68) but the hairy eyes are not rounded at the lower inner edge, the margin being there angulated. Frons black ; the triangle large, shining black, the base nearly filling the space between the eyes ; it extends to the base of the antennae. The antennae have the third joint less pointed than in Becker's figure (I.e. Plate III, fig. 69), being more nearly kidney-shaped : the second and third joints are yellow. The black apical arista is flattened in section and very densely pilose, its two joints being quite distinct, the last ends in a distinct though fine terminal bristle. The proboscis and palpi of the single specimen are completely retracted. Thorax (PI. 16, fig. 5). Shining black on the dorsum and pleurae. The former is finely punctate and clothed with delicate white hairs ; there are no dorsal bristles. The scutellum has a blunt-pointed triangular outline (PI. 16, fig. 5) and is strongly arched and more coarsely punctate than the thorax. It is black with two strong divergent terminal bristles : the dorsum and sides have small white bristly hairs. Wings immaculate, yellow at their insertion ; the venation is as figured by Becker (I.e. Plate III, fig. 70), except that the second vein bends more sharply up to the costa which it meets about midway between the ends of the first and third veins. Halters yellow. Legs entirely pale yellow. 332 PERCY SLADEN TRUST EXPEDITION Abdomen. Basal part orange-yellow, the rest (including the venter) shining black. Size. 1 J mm . exclusive of antennae. Locality. Seychelles. Mahe : marshes on coastal plain, Anse aux Pins and Anse Boyale, I. 1909. Anatrichus, Loew. Anatrichus Loew, Ofvers. Kongl. Vet. Akad. Forhandl., xvii. Dipt. (1860), p. 97. 35. Anatrichus arenaceus Loew, I.e. 97. 13. This insect has a wide distribution in Africa ; it is known from South Africa, Egypt, the Chirinda forest, etc. Locality. Seychelles. Mahe: the collection contains six specimens from the marshes on the coastal plains of Anse aux Pins and Anse Royale, I. 1909. Meroscinis, De Meijere. Meroscinis De Meijere, Tijdschr. voor Entom., li. (1908), p. 172, PI. 4, fig. 14. This genus was established by De Meijere for a Chloropid from Semarang, Batavia. Becker records two species from Africa in the Ann. Nat. Mus. Hung. (1910). There are two species from the Seychelles which can be referred to this genus. 36. Meroscinis ceneifi'ons, n. sp. The colour is uniformly shining black except that the first two or three tarsal joints are bright yellow and that the third antennal joint is veiy slightly rufous, especially on the inner side. Head (PI. 16, figs. 6, 7). The vertical triangle is large, shining metallic blue ; it extends to the front antennal margin where it is abruptly cut off (PL 16, fig. 7). The fronto-orbital bristles are strongly developed, and there is an inner row of strong bristles bordering the shining vertical triangle. The former are slightly bent backwards, the latter forwards and arching inwards towards one another. The post-ocellar pair are crossed ; the outer vertical pair strongly developed. The mouth-margin is bristled. Antennae with an orbicular third joint with a strongly pubescent brownish-black arista. Eyes bare. Tongue and palpi black. Thorax. Shining black, finely punctate and covered with short pale hairs : the single post-alar bristle is fairly strong, the others very small or absent. Pleura shining black and slightly rugose. Scutellum shining greenish -black, more densely punctate than the thorax, the punctation being coarser : it is also covered with pale silky hairs ; two long terminal bristles, much divergent and about as long as the scutellum. Wings with venation as shown in Fig. 19 : glassy with black veins. Halters with black heads but yellowish stalks. LAMB— DIPTERA : LONCHyEID^-E, SAPROMYZIDiE, EPHYDRID^E, ETC. 333 Legs black except for very indistinctly paler knees, the first two joints of the front tarsi and the first three joints of the middle and hind tarsi which are yellow. Abdomen. Entirely shining black with black hairs. Size. 2 to 2{mm. Localities. Seychelles. Silhouette : Mare aux Cochons, plateau and forest above, VIII.— IX. 1908. Mahe : Cascade Estate, about 1000 feet, 1908—9. 37. Meroscinis rugosa, n. sp. This differs from the last species as follows : Head (PI. 16, fig. 8). The shining triangle is not so strongly blue and is pointed at the end. The antennal joints are bright yellow-red with the arista paler and finely pubescent. Thorax. The punctation of both thorax and scutellum is coarser, that of the latter being unusually coarse : the scutellum has a purplish tone of colour and a blunter tip ; there are four scutellar bristles, the terminal pair being situated on small but noticeable papilla?, the two smaller side ones being also on papilla? which are, however, smaller. Fig. 19. Meroscinis ameifrons, n. sp., wing. Wings with pale veins. All the legs have yellow trochanters, black femora with yellow knees, yellow tibia? with a broad black or blackish ring round the middle, and entirely yellow tarsi. Size as last species. Localities. Seychelles. Mahe: Cascade Estate, about 1000 feet; marshes on coastal plain, Anse aux Pins and Anse Royale, I. 1909. Hippelates, Loew. Hippelates Loew, Berlin. Ent. Zeitschr., vii. (1863), p. 36. This genus was founded by Loew for certain American forms. Becker has described one from Madeira (Archiv. Zool., i. 150), and De Meijere one from Java. Five species occur in the Seychelles, one of which agrees with a published description. 38. Hippelates nigricomis Thomson, Eugenies Resa, p. 607. Described from Ins. Rossi. Locality. Seychelles. Mahe : Anonyme Island, I. 1909. 334 PERCY SLADEN TRUST EXPEDITION 39. Hippelates stigmatica, n. sp. This is the smallest of the five species and must be nearly related to H. minor De Meijere (Tijd. voor Entom. li. 168). The latter has black thoracic stripes and entirely yellow legs, while the present species has brownish stripes and the whole of the front tarsi and last joints of mid and hind tarsi black. It possesses the pleural spot of //. minor.