98 



at apex. The parts become so distorted during gestation that their 

 true nature may be easily misunderstood. The position of the 

 spiracles, for instance, is completely reversed. What was originally 

 the anterior pair, finally assumes a position caudal of the true second 

 pair and are placed dorsally. This change of position can be demon- 

 strated by a study of the earlier stages, described below. It will 

 be advisable therefore to speak of the dorsal and ventral spiracles, 

 instead of the first and second pairs. Ventral spiracles small, close 

 to rostrum. Dorsal spiracles large and conspicuous, situated at the 

 base of the stigmatic processes (the so-called *Mac-tubes "), which 

 are prominent but rather short and truncate : the truncate extremity 

 with a circular chitinoas plate, in the centre of which is a shallow 

 cavity with lobular outline bearing numerous minute circular pores 

 and some 5 or 6 larger pit-like depressions communicating with chitin- 

 ous cylindrical ducts (fig. 4,/). Anal process (fig. 4, ^) very pro- 

 minent, the apex strongly chitinous and surrounded by spines and 

 spiniform prominences. Anal ring composed of four broad chitinous 

 plates bearing 10 long stout hairs : the two ventral plates with two 

 hairs each : the dorsal pair each with 3. Anal spine on a stout elong- 

 ate fleshy tubercle : the spine dilated at base, and surrounded by 

 some small chitinous points. Derm with some scattered catenulate 

 groups of minute circular pores on the dorsal surface. Judging from 

 the dried specimens, it is probable that both crimson and yellow 

 forms occur, as is the case in the Ceylonese species T, albizzids 

 Length from 2*50 to 4 mm. 



Early adult female (fig. 4, A.) quite small and very different in 

 form from the insect as it appears after gestation. It may be recog- 

 nised as adult by the presence of the dorsal spine, which appears only 

 in this final stage. The stigmatic processes and perforate plates are 

 at first sessile, and the associated spiracles open dorso^ laterally. The 

 body is trilobate, the lateral indentations marking the openings of 

 the dorsal stigmata which are placed in a more forward position than 

 in the fully grown insect. Viewed from the side (fig. 4, z'.), the anal 

 process projects dorso-posteriorly, while the dorsal spine is directed 

 upwards and forwards. Round the base of the anal process are some 

 irregular crowded groups of glands, each group taking the form of a 

 hollow sphere, the walls of which are closely set with the orifices. 

 In macerated specimens it is difficult to interpret the proper relation 

 of these glands to the surrounding tissues; but they correspond with 

 an area of dense waxy matter which encircles the caudal extension in 

 the living insect. 



Female of second stage (fig. 4, /.), oblong-oval : cephalic extremity 

 narrow and demarked from the thorax by a slight lateral indentation 



