586 ]\Iiss S. L. M. Summers on a new 



aud prosternura ochraceous ; abdomen beneath with a central 

 and marginal series o£ pale ochraceous spots; antennae 

 ochraceous, first joint very long, moderately clavate and 

 castaneous at apex, second and fourth subequal in length, 

 each distinctly shorter than third, extreme apices of second 

 and third black, fourth black or piceous, annulated with pale 

 ochraceous near base ; pronotum (excluding apical area) 

 thickly coarsely granulose, with a somewhat obscure central 

 longitudinal ridge, the posterior angles moderately laminately 

 lobate ; scutellum distinctly, centrally, longitudinally ridged, 

 the apex acute ; membrane shining bronzy, not reaching the 

 abdominal apex ; legs ochraceous, apices of the femora 

 distinctly clavate and castaneous, tarsi with the basal joint 

 pale ochraceous, remainder piceous. 



Long. 8 mm. 



Hab. N. Australia; Port Darwin (J. J. Walker, Brit. Mus.). 



This species was taken during the voyage of II. M.S. 

 ' Penguin/ 



LXVI. — Isotes from the Entomologieal Department of the 

 London School of Trojncal Medicine. — No. II. Description 

 of a new Species of Simulium fro^n the Siamese Hills. 

 By Miss Sophia L. M. Summers, M.A., B.Sc. 



Simuliuvi nigrogilvum, sp. n. 



Numerous specimens of this fly were sent, very kindly, to 

 the London School of Tropical Medicine by Dr. Kerr, of 

 Chiengmai. They were collected by Mr. H. B. G. Garrett, 

 of the Siamese Forest Department, on the hills of Siam east 

 of the Menam, during the months of September and October. 



In view of Dr. Sambon's theory, that Simidium plays an 

 important part in the spreading of pellagra, every reference 

 to this genus is of interest. Only two species of the genus as 

 yet have been described from the Oriental Region, namely 

 Simidium indicum, Becher, from the Himalayas (Journ. 

 Asiat. See. Bengal, liii. pt. 2 (1884) p. 199, pi. xiv.), and 

 Simidium uchile, Meijere, from Java (Tijdschrift voor £nt. 

 Deell. (19U7) p. 206). 



The new form, Simulium nigrogilvum^ is a very striking 

 species. Its colouring is most vivid, almost wasp-like in its 

 contrasts. It is large, its length being almost 3'5 mm. Its 

 head and thorax are velvety black, w'ith bright golden hairs. 



