520 P- E. Keuchenius, 



not, or at any rate not much larger than elsewhere. In so far Sarco- 

 phaga carnaria seems to differ from Sarcophaga haemorrhoa, where 

 according to the drawing given by Dufour, (6, pl. IX, fig. 108), the 

 du et US ejaculatorius, just like in Lucilia caesar, begins with a blad- 

 dery s wollen part. But it may perhaps be, that the presence of such 

 a bladdery swoUen commeiicement of the ductus ejaculatorius 

 depends on the age of the insect, because also in Lucilia we have seen, 

 that this widening may be absent or present. The wall of the ductus 

 is composed of two layers. The tunica externa is only very thin, 

 (fig. 43 ex and fig. 44) and provided with very small nuclei. However 

 it is peculiar, that the lining is formed by a very distinct gland-epithe- 

 lium, of which the cells are often separated by intercellular fissures. 

 They are, however, of different heights, in consequence of which the 

 lumen of the tubes receive an irregulär character. Their nuclei are to 

 be seen near the base, whilst the protoplasm on the side turned to 

 the lumen gets a little more intensively coloured than the protoplasm 

 at the base of the epithelium-cells and shows a very delicate striping. 



The ductus ejaculatorius runs caudally, making many wind- 

 ings. Here the externa changes and it seems to me that a layer of 

 muscle-fibres is added to the outer wall (fig. 45 m), which sometimes 

 tears off during microtomical cutting. Finally the ductus ejacula- 

 torius opens into the sacculus ejaculatorius, whereby just as 

 in Lucilia caesar, the epithelium protrudes a little into the sacculus. 



The sacculus ejaculatorius is provided with an apothetes 

 ejaculatorius and opens out by means of the ductus copulatorius. 

 The outer investment of the sacculus and ductus copulatorius 

 is formed by a layer of larger or smaller cells (fig. 46 o.Z) and the intima 

 is composed of a layer of soft chitin (fig. 46 ch) which sometimes shows 

 a fine dentated or incised margin. 



Pollenia rudis Fab. (Fig. 51 — 54). 



The male genitalia are composed of: one pair of testes, vasa 

 deferentia, accessorial gland-tubes, ductus ejaculatorius 

 and sacculus ejaculatorius (fig. 51). 



The testes (fig. 51 1) are two pear-shaped bodies, which are more 

 pointed at their proximal apex than distally. Both testes are placed 

 more or less symmetrically in relation to each other and ventro-laterally 

 of the gut. Sometimes the left testis is situated a little more cranially 

 than the right, which is just the contrary to what we have observed 

 in the Diptera treated tili now. The testes are turned to each other 



I 



