4^12 Tachardiince. 



tubercle which bears at its apex the characteristic dorsal spine. The only other 

 feature that is noticeable, on a superficial examination, is the pair of minute 

 post-oral lobes, projecting from the under surface. 



After maceration and compression (see fig. 23) other characters can be dis- 

 tinguished. The minute rudimentary antennfc— each consisting of an irregular 

 truncate tubercle with a few stout bristles at its apex— are situated immediately 

 anterior to the mouth parts. The small ventral spiracles {fig. 26) are placed 

 close behind the post-oral lobes, with their apertures directed outwards. The 

 larger dorsal spiracles are situated in a denser chitinous area, immediately 

 exterior to the two stigmatic processes, and are inwardly directed. Each spiracle 

 is associated with a scattered group of small ceriferous pores. The stigmatic 

 processes are mammiform, with a densely chitinous cap {fig. 16) ; in the centre 

 of each is a shallow depression, of an irregularly pentagonal form, in which 

 are numerous ceriferous pores arranged in rosette-shaped clusters ; six or 

 seven of these clusters are more prominent than the remainder (see fig. 27) ; 

 the circumference of the depression is defined by a close palisade of denser 

 cells. The dorsal spine {figs. 7, 28, 29) is slightly curved, stout at the base 

 and tapering to a more or less acute point ; there is a conspicuous tooth-like 

 prominence at its base, on the upper surface, and some smaller and more obscure 

 dentations on the under surface. The spine itself is tubular, with an obscure 

 orifice at its apex. There are, associated with it, numerous clavate gland cells 

 disposed either singly or in small groups, which lie in the fleshy tubercle that 

 supports the spine and communicate by thread-like ducts with the tubular 

 channel {s^tfig. 17). On each side of the body, immediately surrounding the 

 base of the caudal process, is a loose series of compound ceriferous glands (see 

 fig. 23), each of which consists of a compact cluster of pores {fig. 24). The 

 caudal process has a fleshy base and a terminal rigid segment, the distal ex- 

 tremity of which is furnished with a fringe of irregularly toothed and lanceolate 

 spines, incomplete on the ventral margin {see fig. 25). Within this fringe lies 

 the setiferous anal ring, which consists of a more or less confluent series of 

 porous plates bearing ten stout setae. Length of extended insect (under com- 

 pression) 175 to 3 mm. Breadth averaging 2*5 mm. 



The adult male is of a rich crimson colour and may be either apterous (fig. 19) 

 or fully winged. In both forms there is a pair of long opaque-white caudal 

 filaments. In the winged form the antenna: are ten-jointed, and the notal plates 

 are more distinct ; the wing has a pinkish costal nervure. In the apterous 

 form the antennae have nine joints only, and the thorax remains soft and un- 

 developed. The terminal joint of the antenna (in both forms) bears two 

 knobbed hairs at its apex {fig. 21). There are four prominent black ocelli on 

 the head, two on the upper and two on the under surface. The genital sheath 

 is elongate, slender, and sharply pointed ; about two-thirds the length of the 

 abdomen. Length (from frons to extremity of genital sheath) i'^ mm. Both 

 forms of the male are sexually complete. Apterous males were observed to 

 copulate freely with the early adult females, six or seven insects being fertilised 

 by a single male. 



The nymphal test of the female is very much smaller than that of the adult. 

 It is of a more or less symmetrical six-lobed form {fig. 8) ; the lateral areas 

 depressed ; the dorsal area with a medio-longitudinal rounded carina, termi- 

 nating behind at the large posterior orifice. The small stigmatic orifices are 

 situated on the anterior half of the test, on a level with the junction of the first 



