62 Mr. F. A. Bather—Suggested 
Batocrinus Lovet (the formula for all rays except anterior). 
{ ax, olax,. LE Bre2486 
or, more shortly, I-III Br,.4 St. 
This is quite clear, the only point to notice being that in 
the third order of brachials two are fixed, the rest free and 
pinnuliferous. The corresponding formula for Batocrinus 
Christyt is I-IILax,. 8 St. 
Gilbertsocrinus tuberculosus. 
Lax, . Il ax,. [Il ax,....8 St. 
In this case the tertiobrachs are free but bear no pinnules, 
and there are 8 pinnulate arms to each ray. 
One cannot hope to express quite as much in a formula as 
Mr. Puff got into ashake of Lord Burleigh’s head ; it is hoped 
nevertheless that the above examples will show how, by a 
more rational terminology, with its appropriate symbols, the 
aitempt to apply a system of formulation to Paleozoic 
Crinoids may have some chance of success. ‘There are of 
course more complicated plans of arm-branching than those 
here alluded to; they will demand more complicated formule 
no doubt, but it should be possible to use the same terminology 
and symbols in all but the most exceptional cases. 
Interradial Plates.—Interbrachials. 
The term “ Interradials” is applied by Wachsmuth and 
Springer to “ all plates interradially disposed in the calyx.” 
These include Basals, Interradials (s. st.), Interambulacrals, 
and Orals. Now, since all these plates are truly interradial, 
and since all morphologists will wish to retain this wide use 
of the word, it seems a pity to endeavour to restrict it to those 
interradially situated plates alone that occur in the dorsal cup 
and that are above the level of the basals. There is a term 
“ Tnterbrachials,” which Wachsmuth and Springer have 
proposed ‘for all plates between the rays above the radials,” 
thus, by implication, still further limiting the meaning of 
Interradials (s. str.) to the one plate in each interradius that 
may occur between the radials themselves. But morpho- 
logically these latter plates do not differ from the Inter- 
brachials (W. & Sp.) in the same way as radials differ from 
brachials ; consequently the difference of name is misleading. 
