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Subcarboniferous Fossils from New Mexico. 311 
in outline. Third radials a little wider at the upper lateral angles 
than the second radials, pentagonal in outline, and supporting upon 
the upper sloping sides a single pair of smaller secondary radials, each 
of which supports two brachial plates from which the free arms arise, 
except as to the right anterior series (the left anterior series is cle- 
stroyed at this place in our specimen), where three secondary plates 
appear to rest upon the third radial, and support two brachial plates 
each, from which free arms arise. 
A single regular interradial plate fills the space to the top of the 
secondary radials. It rests between the upper sloping sides of the first 
radials, and is bounded on either side by the second and third radials, 
and a secondary radial, and on the top by an interbrachial plate, thus 
giving it nine sides. Its size is about that of a first radial. 
The first azygous interradial is longer. than wide, octagonal, and a 
little larger than the first radials. It supports three interradial plates, 
the central one of which is followed by an interbrachial plate, which 
connects with others extending to the opening in the vault, 
The summit is covered with polygonal, crateriform plates, and a 
strong subcentral spine approaching the azygous side. The opening is 
situated below the base of the spine above the level of the arm open- 
ings, and is surrounded by slightly projecting plates. 
Supposing the left anterior side to be like the right anterior, in 
accordance with the usual structure, the species will have twelve 
arm openings, and if there are two arms to each opening, as is usual 
in the genus, there will be twenty-four arms. 
The plates of the body are all more or less tumid. The first 
radials have an arcuate elevation, and the second radials a tranverse 
enlargement. ‘The whole surface is marked with fine lines, very con- 
spicuous under a magnifier, from which the specific name is derived. 
Those on the body below the arms are longitudinal, but those on the 
vault seem to radiate from the crateriform depressions in the plates. 
PLATYCRINUS POCULUM, 0. sp. 
Plate VII., fig. 4, basal and posterior view, natural size. 
Body of medium size, sub-hemisvherical or deep saucer-shaped. The 
three basal plates forma shallow pentagon less than one fourth the height 
of the cup. The facet for the attachment of the column is subcircular or 
slightly elliptical and full one-third the diameter of the base. The 
first radial plates are twice as large as the basals, subquadrangular, a 
little wider than high, and gradually increase in width from below up- 
