EETH OF THE LAND LEECHES OF CEYLON]

_Haemadipsa Ceylanica_, Bosc. Blainv. These pests are not, however;
confined to Ceylon; they infest the lower ranges of the Himalaya.
--HOOKER, vol. i. p. 107; vol. ii. p. 54. THUNBEBG, who records
(_Travels_, vol. iv. p. 232) having seen them in Ceylon, likewise met
with them in the forests and slopes of Batavia. MARSDEN (_Hist_. p. 311)
complains of them dropping on travellers in Sumatra. KNORR, found them
at Japan; and it is affirmed that they abound in islands farther to the
eastward. M. GAY encountered them, in Chili.--MOQUIN-TANDON,
(_Hirudinees_, p. 211, 346.) It is very doubtful, however, whether all
these are to be referred to one species. M. DE BLAINVILLE, under _H.
Ceylanica_, in the _Diet, de Scien. Nat._ vol. xlvii. p. 271, quotes M.
BOSC as authority for the kind which that naturalist describes being
"rouges et tachetees;" which is scarcely applicable to the Singhalese
species. It is more than probable therefore, considering the period at
which M. BOSC wrote, that he obtained his information from travellers to
the further east, and has connected with the habitat universally
ascribed to them from old KNOX'S work (Part I. chap, vi.) a meagre
description, more properly belonging to the land leech of Batavia or
Japan, In all likelihood, therefore, there may be a _H. Boscii,_
distinct from the _H. Ceylanica._ That which is found in Ceylon is
round, a little flattened on the inferior surface, largest at the
extremity, thence graclimlly tapering forward, and with the anal sucker
composed of four rings, and wider in proportion than in other species.
It is of a clear brown colour, with a yellow stripe the entire length of
each side, and a greenish dorsal one. The body is formed of 100 rings;
the eyes, of which there are five pairs, are placed in an arch on the
dorsal surface; the first four pairs occupying contiguous rings (thus
differing from the water-leeches, which have an unoccupied ring betwixt
the third and fourth); the fifth pair are located on the seventh ring,
two vacant rings intervening. To Dr. Thwaites, Director of the Botanic
Garden at Peradenia, who at my request examined their structure
minutely, I am indebted for the following most interesting particulars
respecting them. "I have been giving a little time to the examination of
the land leech. I find it to have five pairs of ocelli, the first four
seated on corresponding segments, and the posterior pair on the seve