.^0 Tlic Amcrica7i Geologist. November, 1900 
and others had turned out to be nothing but depressions 
lying between the folds, and that such appearances in a sim- 
ilar position were exceedingly common, and were correlated 
in many cases with the existence of articular surfaces on the 
edges of the raised folds as described and figured by me in 
Mastigocriniis and Botryocr'nuis. Pores and articular struc- 
tures could not well coincide, but ligament-scars might 
I'asily be taken for pores. Mr. Springer chooses to regard 
my "few hundreds" as a rhetorical exaggeration; he will 
therefore be interested to learn that of Inadunate crinoids 
showing the ventral sac, there are over four dozen from a 
single horizon and locality in the British Museum alone, 
that the numbers in the Swedish State Museum are certain- 
ly larger, and are rivalled by those in the Woodwardian 
Museum at Cambridge, while I have also examined more 
specimens than I can remember in dozens of other muse- 
ums. This being so I really cannot have my statements 
disputed 'Hn toto," although I will no longer attempt to ex- 
tend it to genera of which I have not made a special study. 
In fact I am now able to confirm Mr. Springer's statement 
as regards the position of certain appearances in some 
American species from ni}- own observation. 
But, wh\', it may be asked, was I formerly so ready to 
extend my conclusions to the specimens studied by Wachs- 
muth and Springer? The answer to this is my second rea- 
son. The first time that those acute and careful investi- 
gators alluded to these structures they wrote as follows: 
"The plates of the ventral sac in the CyatJiocrinidiu are usu- 
ally compartively large, rather thin, hexagonal pieces 
The pores perforate the plate at each angle."* In "■CyatJio- 
cruiidcc'' they then included all Inadunata, and since they 
never, to my knowledge, withdrew this statement as to the 
i:)ores being at the angles, 1 had no reason to suppose that 
"in the Poteriocrinidae . . . without exception the position 
of the pores is the exact reverse of that stated by" — Wachs- 
niuth & Springer. Further, they have never lost an oppor- 
tunity of stating that the supposed pores are on the suture 
lines and "never penetrate the inner portions of the plates 
like the water pores of the Neocrinoidea." (.See "Revision" 
III, p. 66, p. 83, and "Perisomic plates," p. 361). I cannot 
