214 LEONARD DONCASTER. 
others, it is possible that in this point he was mistaken; but, since the absence of the 
corona is a definite part of the diagnosis of S. bedoti, the present species cannot be 
identified with it. 
13. Sagitta septata nov. sp. (Plate XIII, fig. 6.) 
Moderately common both in winter and in spring. 
It is a small species, generally less than 1 cm, The tail segment is a third of the whole. 
The fins are narrow, especially the anterior. There is no epidermal thickening behind the 
head, but the body-wall as a whole is thicker in the posterior part of the trunk than 
anteriorly. There are intestinal diverticula lke those of S. minima. The vesiculae seminales 
are very small. The ovaries are long, extending to the ventral ganglion, and the ova have 
a very curious appearance in fully adult specimens. They become pressed together so that 
they are flattened anteriorly and posteriorly, and the flattened faces have the appearance of 
septa dividing the trunk into a series of compartments on each side. 
In no specimen was the corona well preserved, but it could be seen from the fragments 
remaining that it lies both on the head and on, at least, the beginning of the trunk, 
Hooks 6—8, anterior teeth 6—8, posterior 13—16, rather narrow and pointed. 
The most prominent characteristic of this species is the peculiar structure of the ovaries 
(Plate XIII, fig. 6 and Text-fig. 39). The eggs appear to have 
their shells well developed, and the “septa” are due to the shells 
of two eggs being pressed together. In section it appears that 
when the eggs assume this condition they are already in the 
oviduct, which is greatly dilated, for when followed back the cavity 
containing the eggs is found to open at the usual pore of the 
oviduct; this view is supported by the fact that the large eggs 
lie at the outer sides of the ovaries, next to the body-wall, and  py6. 39, 

Transverse section of 
that no other oviduct is visible, and further that the usual germinal 
epithelium appears between the large eggs and the alimentary canal. 
The animals appear to be undergoing histological degeneration, for 
the alimentary canal has lost its lining cells for the most part, 
and through the greater part of the body is much reduced in size. 
A condition comparable with this is frequently found in S. minima. 
A very similar arrangement of the eggs occurs in a fully adult 
Krohma pacifica in Mr Gardiner’s collection, so that it is not quite 
peculiar to Sagitta septata. 
II. Genus Spadella Langerhans. 
14, Spadella draco Krohn. 
Sagitta septata in the region 
of the ovaries. The ripe 
eggs are represented by oval 
bodies (dotted) lying in spaces 
which are probably the en- 
larged oviducts. The ger- 
minal epithelium is seen lying 
at the inner side of each of 
these spaces, connected with 
the alimentary canal by a 
mesentery. 
Strodtmann, Archiv fiir Naturgeschichte, Jahrg. 58, Bd. 1. 1892, p. 356. 
This species was plentiful in the winter but did not occur in the summer. It agrees 
in every way with the published descriptions. 
I found a number of specimens in which 
the remarkable parenchymatous tissue was entirely absent, and was at first inclined to 
regard them as a new species, but afterwards found some in which part of the parenchyma 
