— 21 — 



alike his younger form (fig. 1 D and E). It will be seen that 

 the antennae are directed f orwards and not so much downwards 

 as in the larva of GàNIN, they are also relatively shorter than in 

 this, and this especially holds good for the processes from 6th 

 segment which are very short and not much thicker than »he 

 antennae, while in the larva of GaNIN they are large, brcad and 

 auriculate. 



Fig. 1 . — Jlnagrus ? subfuscus FORST. 

 A. Egg. — B. 1 st. larval stage, newly hatched. — C. The same, head end separated. 

 D. E. Histriobdellid larval stage. — F. Mature larva. — (Copies from GANIN.) 



If we observe through the translucent egg-shell an Ery- 

 thromma-e.gg, having this stage within itself, the parasite is 

 seen te be very turbulent, it turns and bends in différent direc- 

 tions, so that ail the contents of the egg will be incessantly 

 circulating around it. It moves its mouth-hooklets, and, in 

 contradistinction to the larva of GaNIN the antennae of which 

 are described as immovable, the antennae of Brocheri can be 

 moved and shortened, and even quite retracted. The gut fills 

 most of the body (its limits are indicated in fig. 2 B) and opens 

 in the posterior end of the body. In larvae having reacheJ a 

 size of 0,51 mm (fig. 2 C), I never found any other appenda?es 



