VI. Botryoerinus quinquelobus. 191 
RR 5, of normal shape ; projecting very slightly towards 
the facet, less in No. 2. Measurements are :— 
Width of 
Height. Width below. Width above. facet. 
millim. millim. millim. millim. 
Nowe a 4:8 5°25 35 
No.2 .... 28 35 4-2 (2) 3 
Surface of facet not seen. The radials bend inwards very 
slightly on either side of the facet. 
Arms.—In No, 1 :— 
[Br number 6 and 8. They taper towards the primaxil. 
Measurements of [ Br;—3 millim. high and 3:5 millim. wide. 
Measurements of Tax—4 millim. high. 3:3 millim. wide 
below, aud 4°6 millim. greatest width. 
From the primaxil spring two rather massive irregular arms, 
of rather less width than the primibrachs, bearing small 
armlets at intervals of one, two, or three ossicles. This gives 
the main arms a slightly irregular appearance, but by no ‘ 
means so irregular as in &. ramosus. About 23 brachials of 
what we may call the distichal series are visible, and the 
total length of arm observed is 51 millim. The armlets are 
very small, the width of the first being 1 millim., or about 4 
the width of the main arm at the point where it originates. 
Thus they approach the pinnules of B. decadactylus, but differ 
from them in their irregular distribution and in the fact that 
they apparently branch again. 
In No. 2 :— 
I Br number 5 and 3 and 5(?), Measurements of I Br, 
are—1'9 millim. high and 3 millim. wide. Measurements of 
Tax are—2°25 millim. high, 2 millim. wide below, and 2-5 
greatest width. 
The distichal series are as in No. 1, but the distal part of 
the arms is lost: At the level where the arms are 1°8 millim. 
wide, the armlets that spring from them have a width of °8 
millim. 
Covering-plates, ventral groove, and axial canal are all 
unseen. 
The Stem in No. 1 is preserved to a length of 49 millim., 
but there are indications in the matrix of at least 20 millim. 
more. ‘lhe mean width of the stem, allowing for compres- 
sion, is 4°2 millim., while the lumen, which is pentagonal, 
has a width of -75 millim. In section the stem is quinque- 
lobate, as seen in the outline beside it in the figure. ‘The 
lobes are interradial in position. The ossicles are of three 
sizes: large and projecting ; small and less projecting ; small 
# 
