260 MISCELLANEOUS. 
7. Nereis pHASMA— The Spectre Nereis.—Plate XXXVI. Figs. 16, 17, 11. 
Nothing perplexes the observer more, than inability to obtain a 
distinct view of all the parts of his living subject ; and, perhaps, this 
may be one reason why naturalists have testified such a decided preference 
for studying those poor creatures which they have deprived of life. 
If it be difficult to distinguish the parts of a subject, this must al- 
ways aggravate the embarrassment of determining its systematic posi- 
tion. 
Other observers may have experienced greater facility than has 
fallen to my lot, or, without it, they may have followed the modern 
fashion of those who, disappointed of analogies, institute a new genus as 
the readiest method of solving the problem. 
One evening, early in January, while inspecting a vessel of sea-water, 
my attention was attracted to an indistinct vortex amidst it, without 
presenting any definite object to the view. ‘This motion was connected, 
however, with an air-bubble, certainly shifting it to different parts of the 
vessel. I could account for neither. Nothing else was perceptible, and 
it seemed still more singular, that I should afterwards witness the same by 
day. But on altering the position of the vessel, so as to throw different 
shades of light upon it and its contents, I discovered with much surprise 
that the agent was a very active animal, by no means so diminutive as to 
escape detection, but of such excessive transparence as to disguise its 
form. Nor is this any exaggeration of the fact ; for having sent the 
vessel to an accomplished artist, already named, Mr Peter Syme, for the 
purpose of obtainiga delineation, I found, on reaching him, that he had 
been unable to discover the object. However, by resorting to simi- 
lar expedients as practised by myself, he could now represent the most 
conspicuous parts of the animal. 
Nearly three years afterwards I obtained another specimen in No- 
vember. Both occurred in a capacious jar of sea-water taken from about 
the same place, Newhaven Pier. But with ample opportunities none 
have been again found there. 
