W. H. Leig-ii-Siiarpe 
289 
somewhat serpentine but can easily be traced and they unite together 
before arriving at the female genital aperture. 
Van Beneden and Hesse (from a dissection, and not from sections) 
state that they foimd two uteri full of eggs. In their illustration they 
figure these uteri in the position in which one finds in this and other 
Ichthyobdellid leeches the ductus ejaculatorii, which are, of course, 
full of developed spermatozoa and the large nucleated spermblastophores 
already mentioned. If they really did find uteri full of eggs, the fact 
would be in accord with my suggestions concerning fertilisation and 
development hazarded above; but I think it much more likely, and not 
unnatural, that what they mistook for rrteri were the ductus ejaculatorii, 
especially in view of their figure. 
Generic Characters. Body cylindrical, moderately depressed, 
without papillae or respiratory vesicles, divided though not very 
distinctly into an anterior “neck” and a posterior abdomen, very 
transparent. The leech does not roll itself up when at rest. Oral 
sucker cupuliform, and of moderate size; posterior sucker obliquely 
affixed and very distinct. Annuli only made out with difficulty, and 
the number of annuli to a typical or abdominal somite is still uncertain. 
Testes apparently only five pairs. Bursa insignificant. Pigment cells 
absent. 
Specific Characters. Anterior sucker scarcely as broad as the 
body at its broadest part. Posterior sucker twice as broad as the 
anterior sucker. Eyes absent. Host: Anarrhichas lupus. 
Methods. The leeches I received from Dr Bowman had been 
killed in formalin and preserved in spirit. It is notorious that formalin 
is a bad preservative for histological work, owing, I am told, to the 
presence of traces of free formic acid. This latter should be got rid of 
by adding a trace of caustic alkali to the formalin before use. I find 
it best to slowly anaesthetise the leeches by adding 30 % alcohol, drop 
by drop, to the water containing them, and when they he fully extended 
and uncurled place them in the following hardening reagent, which may 
be regarded as Zenker with the sodium sulphate left out, or as Tellyes- 
niczky with the addition of corrosive sublimate: 
5 g. corrosive sublimate, 
3 g. potassium bichromate, 
5 c.c. glacial acetic acid, 
100 c.c. distilled water. 
