[Footnote 1:  Hirudo sanguisorba. The paddifield leech of Ceylon, used for surgical purposes, has the dorsal surface of blackish olive, with several longitudinal striae, more or less defined; the crenated margin yellow.  The ventral surface is fulvous, bordered laterally with olive; the extreme margin yellow.  The eyes are ranged as in the common medicinal leech of Europe; the four anterior ones rather larger than the others.  The teeth are 140 in each series, appearing as a single row; in size diminishing gradually from one end, very close set, and about half the width of a tooth apart.  When of full size, these leeches are about two inches long, but reaching to six inches when extended.  Mr. Thwaites, to whom I am indebted for these particulars, adds that he saw in a tank at Colonna Corle leeches which appeared to him flatter and of a darker colour than those described above, but that he had not an opportunity of examining them particularly.

[Illustration:  DORSAL.]

[Illustration:  VENTRAL.]

Mr. Thwaites states that there is a smaller tank leech of an olive-green colour, with some indistinct longitudinal striae on the upper surface; the crenated margin of a pale yellowish-green; ocelli as in the paddi-field leech.  Length, one inch at rest, three inches when extended.

Mr. E. LAYARD informs us, Mag.  Nat.  Hist. p. 225, 1853, that a bubbling spring at the village of Tonniotoo, three miles S.W. of Moeletivoe, supplies most of the leeches used in the island.  Those in use at Colombo are obtained in the immediate vicinity.]

[Footnote 2:  Haemopsis paludum. In size the cattle leech of Ceylon is somewhat larger than the medicinal leech of Europe; in colour it is of a uniform brown without bands, unless a rufous margin may be so considered.  It has dark striae.  The body is somewhat rounded, flat when swimming, and composed of rather more than ninety rings.  The greatest dimension is a little in advance of the anal sucker; the body thence tapers to the other extremity, which ends in an upper lip projecting considerably beyond the mouth.  The eyes, ten in number, are disposed as in the common leech.  The mouth is oval, the biting apparatus with difficulty seen, and the teeth not very numerous.  The bite is so little acute that the moment of attachment and of division of the membrane is scarcely perceived by the sufferer from its attack.]

[Footnote 3:  Even men are not safe, when stooping to drink at a pool, from the assault of the cattle leeches.  They cannot penetrate the human skin, but the delicate membrane of the mucous passages is easily ruptured by their serrated jaws.  Instances have come to my knowledge of Europeans into whose nostrils they have gained admission and caused serious disturbance.]

ARTICULATA.

APTERA.

Thysanura.

Podura albicollis.
  atricollis.
  viduata.
  pilosa. 
Achoreutes coccinea. 
Lepisma nigrofasciata, Temp. nigra.