97 



and ensuring the permanence of the three orifices in the wall of the 

 test, namely, the two stigmatic orifices for respiratory, and the anal 

 orifice for excretory and sexual purposes. 



The function of the remarkable dorsal spine still remains a mys- 

 tery. There is apparently no analogous (nor homologous) organ in 

 any other known coccid. It appears only in the adult stage, and 

 might therefore be supposed to have some connection with the repro- 

 ductive process. But Professor Cockerel! has recently recorded 

 species of Tachardia in which this organ is absent. It cannot 

 therefore be an essential part. It is not a mere chitinous spine, 

 but contains a duct connected with glandular bodies. 



Tachardia fid, sp. nov. 



Test of mature $ subglobular in isolated examples (pi. xix, fig. 4, 

 often with supplementary globules of lac attached to the surface. 

 Even where the insects are crowded together and the tests have 

 become confluent, the original form can be roughly distinguished (fig. 

 4, a). Colour bright fulvous or castaneous. Apex pierced with the 

 usual three apertures, the two stigmatic apertures closer together 

 than their distance from the anal orifice : the anal aperture the 

 largest surrounded by a prominent rim : the stigmatic apertures small 

 and slightly sunk, usually blocked by white pulverulent wax. The 

 remains of the larval test occupy a position between the stigmatic 

 orifices. Surface roughened with numerous nodules of lac. Imma- 

 ture tests smaller, more oval and dorsally depressed. Early larval test 

 oblong, with a more or less conspicuous median longitudinal rounded 

 ridge. Diameter of a single isolated adult test averaging about 

 3*50 mm. 



Test of $ (fig. 4, b,) irregularly oblong oval, slightly constricted 

 on each side in front of the posterior orifice, with a median longitudi- 

 nal rounded ridge representing the larval test : a large oval aperture 

 at posterior extremity which, during the pupal stage, is closed by an 

 operculum of lac. Colour dark reddish-brown. Length, i*6o mm. 



Adult $ , after oviposition (figs. 4 c^ d,) oblong oval : placed in an 

 erect position, cephalic extremity downwards. Ventral area some- 

 what concave. Dorsal area rounded. Before oviposition the insect 

 must have been globular, filling the test. Mouth parts with pro- 

 minent spatulate processes arising immediately below the mentum. 

 Antenna (fig. 4, e) small and vestigial : composed of 4 (?) joints which 

 are vaguely indicated by darker chitinous bands ; 3 or 4 stout hairs 



