Ill 
Obs . — The present nol)le speeies is probably one of the largest, if not 
the largest, of the Palceocrinoidea known, equalling if not exceeding the large 
Barycrini, of the American Carboniferous Limestone. The calyx is four and 
a-balf incbes in diameter, and about tliree and a-balf inches in height. The 
anal or posterior side has not been observed, as it is broken away in all other 
examples other than that of the subject of Plate XVIII, Pig. 1, where it is 
bojielessly imbedded in an exceedingly bard silicious matrix. 
It differs essentially from P. Kon inclcl in the possession of protuberant 
infra-basals, and in consequence, when the calyx is normally placed, they are 
visible laterally. 
The stem- joints in this species arc fairly large, measuring quite three- 
quarters of an inch in diameter. 
The form of the two anterior basals is precisely similar to that of those 
of P. Koniiicki, and in the large figured specimen (PI. XVIII, Pig. 1) the 
breadth of the two plates is equal to that of an entire calyx of an ordinary 
sized individual of the species named. A separate plate is represented in 
PI. XXII, Pig. 5, seen from the interior, with the concentric structure- 
sculpture seen both superficially and in section. 
In all the three exposed rays in P. KonuicJd there are two arms to 
the ray. There are two on the left hand ray of P. 2 )rinceps (PL XVIII, 
Pig. 1) hut the right-hand ray is so defective that the number is doubtful. 
On the other hand two are definitely present on the central ray (anterior), 
and perhaps a third. The anterior radial is followc'd by two costals, the first 
triangularly quadrate, the second transversely elongate, or tabular. Whether 
or no this jfiate is axillary I am undecided, but the three next pieces are 
triangular and suhalternate. If the second costal is axillary, these plates 
will I presume be termed distichals ; the third of them is certainly axillary, 
and the pieces beyond will, with the above reading, become palmars. At 
the same time, the second of these triangular plates (distichals) has the 
appearance of being axillary, although too much stress must not he laid on 
this point, from the state of preservation, but it is from this cause that I have 
above suggested the presence of a third arm. 
The figiu’ed example is from the Collection of the Maitland Scientific 
Society, and was obtained during an excursion of tliat body to Mount Vincent 
lla Gi— 92 II 
