306 Transactions. — Zoology. 



the wing, and reaches the costal vein about seven-eighths 

 of the length of the wings. (2 and 3.) The lower main 

 branches form the upper and lower main branches of the 

 cubitus, which branches directly from the primary stalk at 

 B. The upper main branch of the cubitus divides again 

 at C, but neither branch is a continuation of the main 

 branch. The lower main branch of the cubitus divides at 

 N, a longer and convex branch reaches the margin at K, and 

 a shorter branch reaches the margin at L. 



Running from the primary stalk to the lower margin of 

 the wing is an indistinct vein (AM) called the " clavus." 

 In the areas between the branches of the cubitus — namely, 

 DE, EK, KL — are three small triangular markings, com- 

 posed of very small dots ; on the veins of the wing are some 

 very short fine hairs. 



The hind wing (Plate XXXIII. , fig. 2) is larger in com- 

 parison with the fore wing than in either Trioza panacis or 

 Trioza pellucida. The veins are only marked by rows of large 

 dots, and the whole wing is covered with very small dots. 

 The rostrum is pointed and blackened at the tip, ending in 

 the male with three setae (Plate XXXIII., fig. 9), which are 

 entirely absent in the female. 



Length, about 2-25 mm. 



Pupa. — Head generally depressed behind. Eyes large, and 

 of a very dark brown colour. Ocelli three, situated as in the 

 adult. The fringe is very strongly developed, but the indivi- 

 dual rods are longer and closer together than in T. panacis or 

 T. pellucida, and the cups are more or less simply thicken- 

 ings of the lower portions (Plate XXXIV., fig. 2). The anal 

 ring is ventral, and closely resembles that of Trioza panacis. 



Length, about L75 mm. 



Hab. I have found it on Pittospornm tenuifolium, 

 where the pupae lie in little pits both on the ventral and 

 dorsal surfaces of the leaf. Its presence is indicated by the 

 presence of large quantities of a white semi - transparent 

 excretion termed " manna," which fills up the hollows of the 

 leaves, and in windy weather falls to the ground, giving the 

 appearance of a light fall of snow. 



Adult Female. — Generally of a light-yellow colour, with a 

 slight green tint which becomes darker during life, probably 

 due to the green food showing through the semi-transparent 

 skin. Head and thorax not so green as the abdomen. 

 Genitalia are of a dark-brown colour, especially at the tips. 

 The length, including genitalia, about 2-25 mm., and expanse 

 of wings 7 mm. At the posterior and ventral surface of the 

 thorax is a short blunt projection (Plate XXXIII., fig. 7, G), 

 found also in the male, but its function seems to be unknown. 





