30 W. BLAXLAND BENHAM. 
EXPLANATION OF PLATES 2 and 3, 
Illustrating Dr. W. Blaxland Benham’s Paper on “ Fission in 
Nemertines.”’ 
Fie, 1.—View of Carinella (No. 1) immediately after death, showing the 
“segmentation ”’ of the hinder part of the body. (x 6.) A, B, GC, D, indi- 
cate the constrictions in order of depth, 4 being deepest. The drawing also 
shows the general appearance of the worm. pp is the red region of the 
proboscis. The body is coloured orange in the region just in front of 4. 
Fic. 2.—Ventral view of the anterior end, to show the shape of the head. 
M. Mouth. &. Aperture of the rhynchodeum. JZ. Ciliated furrows. 
Fie. 3.—Camera drawing of the hinder end of the worm. A, B, C, D. 
The constricted regions, each marked out internally by a double row of 
nuclei. The section is nearly horizontal. ov. Ovaries, fully developed in the 
hinder “‘segments.” ov’. Less developed ovarian sacs in anterior regions. 
g.d. Genital duct. zt. Intestine. ep. Epidermis. /y. Longitudinal muscle. 
Mag. Zeiss AA 2. 
Fic. 4.—The region C enlarged. The section is at a different level from 
that of the preceding figure, as it cuts the nerve-cord on the left, and does 
not involve the intestine. ep. Epidermis. 4.m. Basement tissue. circ. 
Circular muscles. J/g. Longitudinal muscles. 2. The transverse row of 
nuclei. WV. Lateral nerve-stem. Mag. Zeiss B 4. 
Fic. 5.—Horizontal section through the region D, to show the next stage in 
the process of fission. The longitudinal muscles have ruptured, contracted, 
and left a cavity just below the nerve-cord. 2. A coagulum. 
Fic. 6.—The next stage in the process, illustrated by section through the 
region 4. The ruptured muscles are more numerous, and the cavity (sp.) 
therefore more extensive, and is traversed by connective tissue (c¢.¢.). Mag. 
Zeiss B 4. 
Fic. 7.—Another portion of the same region, to show the coagulum (z.), 
the broken ends of the longitudinal muscle-fibres, and the unruptured base- 
ment membrane (4.m.). 4v. is the lateral blood-vessel. 
Fie. 8.—Portion of A (fig. 3) at a different level, enlarged. The rupture 
has extended nearly right across, and the ends of the two pieces are bending 
inwards owing to the contraction of the circular coat of muscles. This figure 
also shows the flattened epithelium (ep’.) which covers the broken ends of the 
muscles. 
