THE NEMERTINES OF MILLPORT AND ITS VICINITY. 9 
slightly constricted nearer the proximal (base) than the distal end (v. fig. 14). There 
were two reserve sacs, containing respectively one and two stylets. The rhynchoccelom 
had no diverticula. 
The alimentary canal possessed a large number of lateral diverticula, attached by 
strands to the body-wall; a diverticulum was sometimes attached by two strands, a 
slight bifurcation of its extremity being thus produced. When the whole animal was 
examined under the microscope, the diverticula appeared as a series of leaf-like appen- 
dages of the alimentary tract, 7.e. were flattened from before back. 
Examined in spirit several months afterwards, the specimen was about an inch and 
a half long, a millimetre broad, and of a light brown colour; tapering gradually at one 
end, more suddenly at the other. 
Examination of Sections.—-Portions of the animal were sectioned for further 
investigation of certain characters used in discriminating species of this genus. The 
following additional features may be noted :— 
The ventral ganglia of the brain are much thicker than the dorsal. There are no 
neurochord cells or neurochord. The sections confirm the above statements as to size 
and position of the cerebral organs. The ceeca of the alimentary canal can be seen, 
in horizontal sections, sometimes to be bifurcated; the anterior ventral caecum is 
of large size, and sends forwards a pair of diverticula, which do not nearly reach the 
brain. Testes are scattered between the alimentary diverticula but not as a regular 
series alternating with these latter. The (presumably mucous) contents of many of the 
epidermal cells are intensely stained (by Delafield’s haematoxylin). The head-glands 
are not strongly developed. The proboscis, as seen in transverse sections, lies in a 
spacious rhynchoccelom, but is itself of very small diameter, and the proboscis nerves 
are not to be made out. 
Since this form differs from most species of the genus Amphiporus—which are, as a 
rule, somewhat compact and thickset forms—in being thin, indeed filiform when extended, 
I have chosen for it the specific name elongatus. 
I propose the following diagnosis for this form :—Length 75 mm., breadth when 
extended less than 1 mm., filiform. Head tapering, not marked off from body ; 
tail blunter. Colour bright yellow, the same on both dorsal and ventral surfaces ; 
margins whiter. Eyes few in number, in two groups on each side. WStylet shorter 
than its pedestal ; the latter roughly cylindrical, slightly constricted posterior to its 
middle; two reserve sacs. Head grooves two on each side, directed obliquely back- 
wards and mwards on dorsal surface, continued over margin of head on to ventral 
surface. Cerebral organ in front of brain. 
Prostoma (Tetrastemma) candidum (Miill.). 
This worm is commonly found at and near Millport, under stones between tide-marks. 
Previous authorities have differed considerably in the characters which they attribute 
to the species ; the following account may therefore be of interest. 
