512 



STUDIES IN LIFE-HISTORIES OF AUSTRALIAN- DIPTERA BRACHTCERA, 1., 



side of the vessel, adheriug tu one anollier laterally, and to the vessel liy means 

 of a stieky substance with wliich they are coated (Text-fig. 5a). But all the 

 others laid in tubes, as well as those obtained in the single instance in which 

 one female oviposited on soil in a Ijreeding cage, formed one or two clumps, 

 the eggs being- jiiled up iriegularly on one anotlier, though often remaining in 

 contact at the pole (Text-tiy. 5?'). 



Text-figs. P-8. Posterior end of larva of 

 RI. rubriceps. 



Fig. 6. Lateral view. Fig." Dorsal 

 view. Fig.8. Ventral view, (x 10). 



Text-fig. 5. a. Egg cluster ^[. ruhriceps. (x 5); 

 ^, eg^ cluster. (xlO); c, single egg. (x.32); 

 d, sculpturing on chorion of egg. (x 19.S) . 



The number of eggs dei)osited. in each case, by four females was carefully 

 counted. The numbers were, respectively, 130, lli3, l(i4, and 181. If these 

 tigures represent anything like the normal nund)er, the fecundity of this species 

 is much lower than is the case with Strdtiiniii/io clnnnaeleun Beg., for which Mik 

 (1896) gives the figure 630. 



The Eijcj. 



Tiie eggs are opaque white in colour, and elongated oval in outline, slightly 

 broader at one end tlian the other (Text-fig. 5c ) . They measure from .80 to .88 

 mm. lu length, and .22 to .27 nun. in diameter. The chorion is thin, and its 

 surface shows a very delicate sculpturing in the form of an irregular network 

 of raised lines enclosing polygonal-sluiped spaces (Text-fig. 5rf). This marking 

 can only be seen under high magnification, and when the chorion is torn away, or 

 freed fi'oin the internal contents of the eggs by clearing. Treatment with caustic 

 potash, or willi clearing agents, such as clove and cedar oil, did not give good 

 results, but more sicccss was obtained when the eggs were immersed in chloro- 

 form, an<l afterwards cleared in xyjnl. Tlu^y tlien mounted fairly well in Canada 

 balsaiii. 



F.cdiis'ix. 



1 ha\(' liein umililc l<> dctermiiu' the total Muml)er of ccdyses occurring during 

 the larval ])eriiid. Oiilv niic of tlu- larvae kept in the laboratory has been ob- 

 served to mnult Iwice. once on tlii' 3ril December, and the second time on the 



