ON A NEW ENTOZOIC COPEPOD FROM JAPAN. PA | 
Goidelia japonica—a New Entozoic Copepod from Japan, 
associated with an Infusorian (Zrichodina). By Attce L. 
Emereton, B.Sc. (Communicated by Prof. G. B. Howes, 
Sec. Linn. Soc.) 
[Read 15th November, 1900.] 
(PuatzEs 21 & 22.) 
WuiLE working last spring in one of the Laboratories of the 
Royal College of Science, London, on the structure of Echiwrus 
uniemetus *, an almost unknown Japanese Gephyrean obtained 
for me by Professor G. B. Howes, my attention was arrested by 
the constant occurrence of a parasitic Copepod in the rectum: 
it was always present in great numbers, along with an Hntozoic 
Protozoan which, so far as I can determine from preserved 
material, is a new species of Trichodina (Pl. 22. fig. 20, 1., i1., 11. 
—see note infra, pp. 227-8). Though this soft-bodied unicellular 
creature was not sufficiently well preserved to give satisfactory 
results as to its detailed structure, the Copepod was in good 
condition. In my work upon this parasite I have been greatly 
assisted by Mr. M. F. Woodward, whose suggestions and advice 
have been most valuable. The microscopic size and extreme 
brittleness of the animal rendered dissection difficult, and 
necessitated the use of many different stains and reagents. Jam 
especially indebted to Mr. Woodward for his experienced aid in 
the micro-chemical part of the manipulation. 
On opening the rectum of the host, large numbers of the 
parasite are seen free in the contained fluid; many of them, 
however, are invariably attached to the epithelial lining of the 
rectum. On trying to remove these it is found that they are 
adhering very firmly, the anterior end being more or less em- 
bedded in the host’s tissue; and after they have been detached 
(with a moderately stiff camel’s-hair brush) little crypts, or scars, 
remain showing the places where the parasites had been situated. 
The length of the body—without the caudal sete—is about 
‘5mm. to:7mm. Pi. 21. fig. 1 is a scale-drawing of an adult 
female (A), an adult male (B), and an immature female (C); it is 
a camera-lucida drawing, in which the specimens were magnified 
* rans. Linn. Soc.. Zool. ser. 2, vol. viii. part 3. 
15* 
