NOTE ON ZYGODON FORSTERI MITT. 85
44. WHITEHEAD, H. (1911). : Dutrochet's Land Leech in Essex.
Essex Naturalist, XVI, pp. 219-221.
45. WHITMAN, C. O. (1898) : Animal Behaviour. Biol. Lect. Marine
Biol. Lab. Woods Holl. Mass. (See also Distant. Zoologist (4)
V. (1901) p. 235.)
(A full bibliography of the subject is given at the end of Harding's paper.)
EXPLANATION OF PLATES.
PLATE VI.
Fig 1. Piscicola geometra,
,, 2. Protoclepsis tessellata,
,, 3. Hemiclepsis marginata,
,, 4. Glossosiphonia heteroclita,
,, 5. G. complanata.
„ 6. Helobdella stagnalis
PLATE VII.
Fig. 7. Herpobdella atomaria.
,, 8. H. atomaria, showing positions of genital pores.
,, 9. H. octoculata, showing positions of genital pores.
,, 10. Haemopis sanguisuga.
,, 11. Hirudo medicinalis.
,, 12. H. medicinalis, details of pattern on dorsal surface.
,, 13. H. medicinalis, details of pattern on ventral surface.
(Figs. 11-13 are drawings from a specimen taken in the New Forest).
,, 14. Trocheta subviridis.
(Drawn from a specimen taken at Theydon.)
NOTE ON ZYGODON FORSTERI MITT.
By PERCY THOMPSON.
THE recent re-discovery by my wife of Zygodon forsteri
Mitt., one of our rarest and most local British mosses, in or
close to its first recorded habitat in Epping Forest, has been con-
sidered by the Editor of sufficient interest to warrant the following
note on the few occurrences of this moss hitherto recorded. The
moss was first noticed by T. F. Forster at some time prior to 1794,
on a felled tree-trunk in a timber-yard at Chapel End, Waltham-
stow, which trunk had most probably come from the
neighbouring forest.
For many years no second occurrence of Zygodon forsteri was
noted, save a dubious record from Sussex, by E. Jenner, which
has never been verified.
In 1879 Miss I. Gifford found a specimen in a field at Minehead,