200 Mr. F. A. Bather on British Fossil Crinoids : 
The Stem attained a length of at least 11 centim. It was 
round in section, with a width 
(in 57048) of about 4°5 millim. 
In the proximal region it is com- 
posed of ossicles of three sizes, 
the larger ones slightly pro- 
jecting, with an average height of 
‘4 millim. (zincotype, fig. 5). In 
the more distal regions (fig. 10) the 
ossicles are smooth and more equal 
in height. * The sutures are crene- 
late, indicating radiate striz on 
the articular surface. The lumen 
is small, as in Botryocrinus, and 
from it there proceed five radial 
sutures, which are usually visible 
on the outside right up to the 
dorsal cup. In the distal region 
of the stem the pentameres show 
only a slight tendency to the 
hexagonal shape and semi-alter- ( 
nating arrangement described for 
Lotryocrinus. The  distalmost \ 
end of the Cambridge specimen 4;,. 19, Distal part of Stem in 
is smooth and rounded, and this “the larger Dudley Museum 
though the whole stem and cup specimen of M. loreus. (x 
are very slightly disturbed. If 33 diam.) 
this rounding be due to weathering, it would appear to 
have been accomplished while the creature was yet alive. 
(Pl. XI. fig. 3.) 
GENERAL REMARKS ON THE GENUS. 
In the composition of its cup, in the anal area, and in the 
simple dichotomy of its arms, this species resembles the species 
of Cyathocrinus, and, were that genus not more strictly defined 
than it has hitherto been, it would doubtless be referred 
thither. On the other hand, there are many points, not 
hitherto recognized as of great importance, in which the 
present species resembles a very different assemblage of 
Crinoids. The shape of the cup, especially of the radials, is 
the same as that of Botryocrinus. The ventral sac is of the 
same structure as that of Dendrocrinus, Botryocrinus, and 
Thenarocrinus ; while the general resemblance of the smaller 
Dudley specimen to the type specimen of 7. gracilis (Brit. 
Foss. Crin. IV., ‘ Annals,’ ser. 6, vol. vii. pl. i. fig. 4) cannot 
pass unnoticed, The arms are especially like those of 7. 
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