121 
67 r^s. 9 -ECIIINODERMATA. 
Orc^er-CEINOIDEA/ 
SYNBATIIOORINUS— 
Synbathoceintjs ogivalis, L. G. de Koninclc. 
PI. VI, Pig. 1. 
Tlie calyx is small, and shaped like a rather short truncated cone. As 
in all the species of this genus, the basal plate is single and hut slightly 
developed, having a length of only one millimetre, although its diameter may 
he five millimetres. The surface hy which the basal plate is united to the 
column is circular and slightly depressed, with a diameter of three milli- 
metres ; in the centre is a very small circular aperture corresponding to the 
canal of the column. The five radials which complete the calyx have all about 
the same size and shape; this shape is that of an inverted equilateral triangle, 
with a truncated apex by which they are joined to the basal plate. The 
surface of each radial hears three folds, which, having a common origin in 
the centre of each piece, are directed, one vertically towards the base, and 
the others obliquely right and left towards the two lateral angles, thus 
duciug a design something like a capital Y. juxtaposition of these 
radials, and the junction of the extremities of their ornamental folds, hollows 
are formed, comparable to those of Gothic arches, easy to comprehend from this 
design YYY. Their articular edges are large, and sloj)e a little from back 
to front. 
Distinguisliing Characteristics. — Sgnbathocrinus ogwalis cannot be 
confounded with S. conictis, Phillips, the only species of this genus really 
known, because its cup is much shorter and more expanded, and above all it 
has some segments that are entirely wanting in S. conicus. 
Formation and Localitg. — A single specimen of this pretty species 
was found in a yellowish, argillaceous, friable limestone at Burragood, on the 
Paterson. 
POTERIOCBINUS, Miller. 
Among the Carboniferous fossils submitted to me for examination I 
have found only two fragments which may belong to this genus. One is a 
' I must point out that in tbe descriptions of tlie species I have emjjloyed the nomenclature laid down in 
my “ Monographie des Crinoides carboniferes dc Belgique.” 
