1 al Sate ge Sy ih 
a eli ill oh gts nlp Sec becnigpmesh cha pes AT aR sma b= mb ga ite Ia li lag Da a aa rR eo 
H, L. Smith on the vegetable nature of Diatomacee. 83 
Dr. C. A. White, at present State Geologist of Iowa, in a 
paper on the same subject, (Bost. Jour. N. H., vol. 8, pp. 481- 
488,) describes P. Norwooditi Owen and Shumard and P, stel- 
liformés, id., as having a similar structure—but he goes fur- 
ther,—he considers the central orifice “not to be the mouth,” 
and I believe that he is the first naturalist who ever published 
such an opinion. His idea of its function is thus expressed : 
“Tt seems more probable that as the ova were germinated within 
the body, they found their exit through the central aperture, 
and were pace along the small central grooves of the 
pseudambulacral fields before mentioned, beneath the plated 
integument, to the bases of the tentacula, where they were de- 
veloped: and discharged as in the true crinoids.” I perfectly 
agree with Dr. White in this view. The central aperture is 
not the mouth, in fact it is not a natural orifice, but a breach 
the vault. The true natural orifices - is part are those 
that I have discovered in P. conoideus as above mentioned. 
They are the homologues of the ovarian pores at the bases of 
the arms of caryocrinus and in part, as I shall show in another 
part of these notes, of the ambulacral orifices of the true cri- 
noids. 
Her Rice the basal, radial and interradial. Mr. Lyon has ad- 
vanced the opinion that there are three small plates below 
those now called the basals (Geol. Ky., vol. iii, p. 468, pl. 1, 
. lc). I have examined a number of specimens with refer- 
ence to this point and I think heisright. There are three small 
pentagonal basals, the two upper sides of each of which are 
excavated to receive the sub-radials, i, e., those at present de- 
signated “‘ the basals.” They are, in general, anchylosed to the 
subradials, but in one of Mr, Lyon’ s specimens that I have seen 
they are distinctly separate. 
[To be continued.] 
Art. [X.—Spectroscopic examination of the Diatomacee ; by 
H. L. Smiru. 
marked results from the is aloe of the spectroscope. I 
have been enabled to prove the absolute identity of uae 
or the green endochrome of plants with diatomin or the oli 
yellow endochrome of the Diatomacee, The s 
