The Relation of Nucleoli to Chromosomes in the Egg 
of Cribrella Sanguineolenta Lütken. 
By 
H. E. Jordan, 
Associate Prof, of Anatomy. üniversity of Virginia, U.S A. 
With 9 figures in the test. 
The special interest in this egg is enhanced by reason of a close ge- 
neral resemblance to tliat of Echinaster crassisphm, previously described ^), 
coincident with striking differences in details. 
The two examples of the Echinasteridae here mentioned, in con- 
trast with most Asteroidae, do not have free-swimming young. The eggs, 
always few in nuinber, are collected on the adoral surface where they 
develop as described by M. Saks 2 ), under the shelter of the arms. The 
latter simply bend round over the brood, forming a temporary charaber. 
In both species the eggs are of remarkable size and contain large eccentric 
nuclei. The finely granulär cytoplasm is packed with large clear alveoli 
probably filled with attenuated yolk. The cytoplasm appears identical 
with that figured for Echinaster. 
The material upon which the following description is based con- 
sists of a nnniber of ovaries collected at the South HarpsweU Laboratory 
during the Summer of 1908, and a half dozen free eggs taken from the 
„brood-chamber“ of the same species found at Newport, E. I., kindly 
given to me by Professor Johx H. Gerould of Dartmouth College 3). 
1) JoRDAX, H. E. The Germinal Spot in Ecliinoderm Eggs (Papers Tortugas 
Lab. Vol. I). Carnegie Instn. Wasliington, Pub. 102. 1908. 
2 ) Sars, J[. Über die Entwicklung der Seesterne. Arch. Xaturg. Jahrg. X. 
Bd. 1. 1844. 
2) I am further indebted to Prof. Gerould for valuable suggestions regarding 
the procuring of material. 
