28 
TICTORIA MEMORIAL MUSEUM. BULLETIN NO. I 
the series of collecting basins in the outer circular canal to the 
mouth, which would be central and beneath the plates of the 
disk. 
A specimen in Mr. Narraway’s collection is of especial interest 
because it shows the opposite side of the animal. It is a small 
specimen, and probably immature (see fig. 3). The plates have 
a somewhat different ornamentation from those of Cyclocys- 
ioides halli , but there is no positive evidence that it does not 
belong to that species. The specimen is 7 mm. in greatest 
diameter, and the sub-marginal ring is composed of 19 heavy, 
wedge-shaped plates of variable size. Most of the plates are 
about one-half longer than wide. The sub-pentagonal form is 
due to the fact that five of the plates, separated by groups of 
from 2 to 4 plates, are stronger than the others. Each of these 
stronger plates appears to be directly facing one of the central 
small plates surrounding the central opening. Between the 
19 strong plates of the sub-marginal ring are grooves, covered 
by narrow, convex, smooth plates, or more probably, by secon- 
dary deposits of calcite. The large plates are covered with small 
pits, between which are rounded, inosculating ridges. The 
corresponding plates in C. halli are ornamented with large 
Fig. 3. Diagram of Cyclocy&toides . 
From Narraway collection. 
tubercles. Within the sub-marginal- ring is a sub-circular area, 
4 mm. in diameter, in the centre of which is a minute opening, 
surrounded by an elevated ring of 5 plates. This may be an 
anal opening. The remainder of the disk is covered by small 
plates which seem to be arranged in a somewhat radial fashion, 
with larger plates towards the centre and very small ones at the 
outer margin. Adjoining the sub-marginal ring, there seem 
