Meek and Worthen on Paleozoic Crinoidea. 29 
one or more of the outer turns removed, has an oval or subel- 
liptic form, being contracted and twisted at both ends, so as 
to present very nearly the appearance of the shell of some spe- 
cies of Ovulum. Its walls are quite thin, and seem to form 
more convolutions than in any other species in which we have 
had an opportunity to examine it. As seen by the aid of a 
CN aE Pee eI: Se en 
appearance, being composed of a great number of minute 
pieces, with numerous openings passing through between them. 
The little pieces and the openings between them are of nearly 
uniform size, and arranged so that there are usually one or 
two of the former intervening between any two of the openings. 
Another of Mr. Wachsmuth’s specimens of Actinocrinus 
securus Hall, has one side of the body removed so as to show 
about two thirds of the convoluted organ, the upper part of 
which is broken away. The part remaining has a short wide 
subcylindrical form, with a rather broad, obliquely truncated 
lower end, which is not tapering, as in the other species. 
Under a magnifier it is seen to be composed of an extremely 
fine net-work, far surpassing, indeed, in delicacy of structure, the 
finest laces that it is perhaps within the power of human skill 
Se ak i ak a a ae bt 
es ee a oe 
Paw ey eas ee eee say ee 
handled with great care, as a mere touch of this delicate part 
would probably cause it to fall into hundreds of minute frag- 
ments. On examining it under a magnifier, the little bars of 
which it is composed are seen not to intersect each other at any 
mane angle, but ——— so as to impart a kind of irreg- 
ular ity, may so speak, to the form and size of 
the Pe tone Of pier little bars there are two sizes, the larger 
forming the larger meshes, while within the latter a smaller 
4 set of processes extend partly or entirely across, sd as to form 
‘more minute meshes ; the whole presenting a beautiful appear- 
ance, of which it would be difficult to convey a correct idea by 
a mere description alone, without the aid of figures 
rom analogy, judging from what is known of the internal 
structure of the recent genus Comatula, in which several au- 
thors have noticed a reticulated calcareous structure secreted 
Sot er 
RES Sa ee Se eS 
sufficient dense structure of this ind me leave ve races 
istence in a fossil state. 
