Echinoid Radioles, Anaulocidaris. 1 9) 
Having, however, oriented the blades according to the bevels, we see that they 
are much less symmetrical than in the other forms. Even in the six-sided blades 
of this form the handle is often conspicuously shifted to one side; in most of the 
specimens preserved that side happens to be the W. as seen from the under 
surface, but this I regard as accidental. In the five-sided forms, owing to the 
absence of the S. side, this shifting of the handle is correlated with a shortening 
of the SW. side when the handle is moved towards the W. and of the SE. side 
when it is moved towards the E. In these specimens the shifting appears to be 
indifferently to the E. or W. 
The inner face of the six-sided blades is like that of the trulliformes, except 
for the greater narrowness of the handle and the flattening of the surface on the 
S. side of it. In the five-sided blades, however, the concavity between the handle 
and the NW. and NE. corners disappears, and the surface may become convex. 
The outer face, which is convex in the six-sided blades, becomes flatter in the five- 
sided ones, but never concave. 
The striated ornament is not visible on any of the radioli paletiformes. 
Comparison of A. ftestudo with A. Buchi. 
Before discussing the relations of the various radioli to one another and to 
the test, it will be as well to consider such further information as can be obtained 
from A. Buchi. A good deal has been written about that species, but no connected 
account of all the forms of radiole has ever been given, nor have their relations 
been quite correctly understood. Thanks to the abundant material of A. testudo, 
it is now possible to imagine a correspondingly complete series of radioles for 
A. Buchi, and to place the various specimens scattered through several museums into 
their places in that series. Since most of the specimens are incomplete, outline 
figures are given, sometimes restored in a dotted line. Lines pointing to various 
regions of these figures indicate the exact levels at which certain of the measurements 
were taken. All measurements are given in millimetres. 
1. Radioli remiformes. 
(Pl. X, figs. 248, 249.) 
The specimens examined are the following: 
(MM) In the Palaeontological Museum, Munich. 
a) Poa 
Actual length 18°7 
Estimated length . . . . 22°5 (24°3 inMonsrer’s 
Greatest width: . . . . 96 reconstruction) 
Width of annulus. . 5 Oe 
Thickness of annulus a 12/4 
Text-fig. 27. 
