290 
Platybclella Anarrhichae 
The leeches are to be left in this solution one or two days, according 
to size, and afterwards washed in water, and passed through alcohols 
of increasing strength beginning with 15 %. 
The microtome-cut sections, for seeing the cocoon gland cells and 
other tissues, should be stained as follows: 
Haemalum 5-10 mins. 
Wash in running tapwater. 
Eosin (in 90 % alcohol) 5-10 mins. 
If it is not desired to decolorize with acid alcohol the minimum time 
mentioned should be observed. 
For observations of whole unstained specimens in bulk, I find that 
creosote as a clearing agent on the wdiole does not act so w r ell as oil of 
cloves. For one thing creosote is apt to turn pigmented leeches, like 
Calliobdella, black. I do not advocate mounting the entire leeches in 
Canada balsam; in my experience the internal structure can best be 
observed in leeches in oil of cloves in a watch-glass. Do not keep the 
leeches in oil of cloves. I preserve my type specimens in a tube of 
xylol, and transfer them to oil of cloves in a watch-glass for examination. 
(My thanks are due to Mr J. T. Cunningham of the South-Western 
Polytechnic, London, S.W. for his kind assistance, to Mr Gerald Boyce, 
arid to Mr F. Maurice-Rey for reproducing the figures from my rough 
sketches; the assistance kindly rendered by other gentlemen has 
already been acknowledged in the text.) 
REFERENCES. 
Blanchard (1894). Hirudinees de ITtalie. Boll. Mus. Zool. Torino, ix, No. 192. 
Bourne (1884). Contributions to the anatomy of the Hirudinea. Quart. Journ. 
Micr. Sci. xxiv, 419. 
Diesing (1858). Revision der Myzhelminthen. Alcad. Wien, xxxin. 
Henry (1912). Haemogregarina anarrhichadis from Anarrhichas lupus the catfish. 
Parasitology, v, 190. 
Johansson (1896). Bidrag till Kannedomen om sveriges Ichtliyobdellider. Upsala. 
- (1898). Die Ichthyobdelliden im Zool. Reichsmuseum in Stockholm. Oversigt 
af k. Vetensk.-Akad. Forhandl. No. 9, 665. 
Leigh-Sharpe (1914). Calliobdella lopliii. Parasitology, vn, 204. 
Malm (1863) (paper read 1860). Svenska Iglar—Disciferae. Goteborgs Kongl. 
Vetenslcaps. Handl. vm, 153. 
Van Beneden and Hesse (1863) (read 8. xi. 1862). Recherehes sur les bdellodes 
ou hirudinees, et les trematodes marins. Mem. de VAcad. r. des Sci. de Belgique, 
xxxiv. 
