46 Dr. T. Wright on new Species of Echinodermata 
planted on the flat basal plate, and its sides support the se- 
condary rays ; these are ten in number, and consist of from ten to 
eleven circular plates, each differing in form and thickness from 
the other, their articular surfaces being smooth and undulated 
in different directions, the elevations of the one plate always 
corresponding to the depressions of the other with which it is 
articulated ; these inequalities are well seen in the specimen 
before us; from the various angles at which these plates lie in 
relation to each other, the ultimate brachial piece of each of the 
secondary rays has a triangular form externally, the sides of 
which support the tertiary rays ; these, like the secondary rays, 
consist of unequal-sized plates with undulated articular surfaces, 
which are marked with fine lines that radiate from the centre to 
the circumference ; the number of the elements in these ter- 
tiary rays cannot be accurately made out in consequence of the 
imperfection of this part of the skeleton ; judgmg however from 
the remains of the plates in a part of the slab once occupied by 
a tertiary ray, we estimate their number to have been from fifteen 
to twenty. The inferior surface of the centre of the calyx ex- 
hibits a depression produced by the convexity of the brachial ele- 
ments and the prominence of the heart-shaped basal pieces ; into 
this depression the summit of the column closely fits, It is 
unfortunate that so small a portion of the column of this 
Crinoid is preserved, as it is possible that the lower part of the 
stem was different from that which is preserved ; the upper part 
of the column before us consists of thin star-shaped plates, the 
rays of which are deeply divided, and their surfaces are sculptured 
with well-marked transverse articular processes ; between every 
third plate a thicker and broader plate is introduced ; the side- 
arms appear to have been numerous about the upper part of the 
column ; they were composed of thin circular plates havg un- 
dulated surfaces similar to those observed on the secondary and 
tertiary rays. 
Affinities and differences.—Pentacrinus Goldfussii resembles in 
some points P. tuberculatus, Mill.: through the kindness of 
Major Austin and Mr. Etheridge we had the privilege of comparing 
our fossil with Miller’s type specimen in the Bristol Museum, but 
the imperfection of that Crinoid makes a rigorous comparison 
impossible ; one point of difference which Miller thought specific 
of P. tuberculatus he thus describes : “The column differs in its 
joints, being thinner, and their having been covered all over with 
a more conspicuous muscular coat, which shows itself in nume- 
rous minute tubercles the result of its contraction * :” this cha- 
racter is certainly absent in our fossil. It is distinguished from 
* Miller’s Crinoidea, p. 65. 
