VII. Mastigocrinus loreus. 201 
gracilis, and in a less degree like those of T. callipygus; they 
resemble them not only in their excessive dichotomy, but in 
the character of the brachials and of the covering-plates. In 
all these respects they differ from the arms of the Cyatho- 
crinide, and in all except the regular dichotomy they resemble 
the arms of Botryocrinus. In the presence of radial sutures 
and in the arrangement of the columnals the stem resembles 
that of Ottawacrinus, Thenarocrinus, and Botryocrinus, but 
approaches nearer the last by reason of its smaller lumen. 
From all these facts, then, it appears that the species must 
find a place in that line of genera that passes trom Dendro- 
crinus and Ottawacrinus to Botryocrinus and its allies. 
When we inquire into which family it should be placed, the 
obvious answer is—the Dendrocrinide ; since the possession of 
regularly dichotomous arms precludes it from finding a place 
in the Decadocrinide. Further, from the non-pinnulate * 
nature of its arms, it must be placed with the Dendrocrinites. 
Comparing it now with the other Dendrocrinite genera, we 
see that it differs from Dendrocrinus, Homocrinus, Pariso- 
crinus, and Thenarocrinus in the total absence of a radianal, 
in which respect it resembles Merocrinus and Ottawacrinus. 
In Merocrinus, however, no anal plate of any kind enters 
into the dorsal cup, so that we are driven back to Ottawa- 
crinus. 
Ottawacrinus, it will be remembered, has an anal a placed 
between the radials, but no radianal (see Brit. Foss. Crin. IL., 
‘ Annals,’ ser. 6, vol. v. pl. xiv. fig. 12); in the main com- 
osition of its cup, then, it resembles the present species. 
The stem of Ottawacrinus, too, has very distinct radial sutures. 
Our new British species cannot, however, be referred to 
Ottawacrinus, for in that genus the anal & is raised by hal. 
its height above the general level of the radials, while its 
upper surface supports only two plates of almost equal size. 
In Ottawacrinus, moreover, the shapes of both basals and 
radials are curiously irregular on the right side of the cup. 
The brachials of Ottawacrinus are much flatter, and the 
articular facet extends over the whole width of the radial, so 
that the arms are closely pressed together below. For the 
loan of the type specimen of Ottawacrinus canadensis I here 
tender my hearty thanks to its owner and describer, Mr. W. 
R. Billings, of Ottawa. 
This new species, then, appears to be sud generds, and it is 
unfortunately necessary to add to our lists the name Mastigo- 
crinus. ‘This genus may be regarded as leading in one 
direction towards the Botryocrinites, and in another towards 
the Cyathocrinites. 
