— 22 — 



than the mouth-hooklets. Whether the antennae and the pro- 

 cesses from the 6th segment hâve disappeared on account of a 

 mère distention of the body-wall or after an ecdysis, I hâve not 

 been able to décide, I however think after an ecdysis. In the 

 interior of the body, the imaginai dises and the shape of the 

 pupal organs now can be seen (fig. 2 D), in the gênerai features 

 as in the larva of G.4N1N. I he largest larva measured had a 

 length of 0,63 mm. 



D 



Fig. 2. -- Jnagrus grocheri SCHULZ. 



A. Ist larval stage, head end separated. — B. Histriobdellid stage. 



C D. Mature larva, in the latter the pupal organs are seen. — (Ail figures enlarged X 100.) 



It seems as if the Histriobdellid stage is peculiar to the genus 

 Anagrus, as besides the two hère mentioned species (Brocheri 

 and subfuscus) we also are acquainted with a third species, Bar- 

 theli TuLLGR. (I) in which a Histriobdellid larva occurs. The 

 larva of Bartheli represents an intermediate form between the 

 two others, in as much as the mature larva has mouth-hooklets 

 and short antennae but no processes from 6th segment. 



(1) Meddel, N" 132, Centralanst. forsokvâs. jordbruksomr. Stockholm, 



3916, p. 9. 



