170 _ WELLER AND DAVIDSON 
family, they are perfectly rigid, standing out horizontally from the 
calyx and are entirely distinct from one another. They are also 
not nearly so greatly developed in Petalocrinus as in Crotalocrinus. 
Fig. 2.—Idealized view of the ventral surface of an arm of FPetalocrinus mirabilis. 
The diameter of the stem is small, while in the Crotalocrinide it 
is almost as great as that of the entire calyx. 
PETALOCRINUS (?) MAJOR (2. Sp.). 
JPIEMI. Wiley 1SHEZS The 
A single imperfect specimen differs materially from the speci- 
mens of P. mirabilis. The calyx is entirely unknown, but from 
the arm structure it is placed provisionally in the genus Petalo- 
crinus. The arms differ from P. mirabilis in being much larger 
and in being in lateral conjunction. The arrangement of the 
ambulacral grooves cannot be determined as the ventral surface 
is imbedded in the matrix. In the great expanse of the arms 
and their lateral conjunction this species approaches more nearly 
to the arm structure of Cvotalocrinus, but differs from the species 
of that genus in their apparent rigidity. 
GONIOPHYLLUM PYRAMIDALE* /fisinger. 
Plate VI., Figs. 6-8. 
829. Turbinolia turbinata var. Pyramidalis Hisinger. Tableau des petrif. 
deysuede edt jp 22. 
1831. Zurbinolia pyramidalis, Hisinger. Tableau des petrif. de Suede, Ed. 
Bs (Oo AGs 
1851. Gontophyllum pyramidale Milne Edwards & Haime, Polypiers fos- 
siles, p. 404, Pl. 2, Figs. 4, 4a. 
‘For a complete bibliography of G. Ayramidale, see Dr. Lindstrom’s paper on the 
operculate corals. 
