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Nachdruck verboten. 
On the early Development of Lepas fascicularis. 
(A Preliminary Note.) 
By Mavcrice A, BieEnow. 
(From the Zoological Laboratory of Northwestern University, 
Evanston, 11l., U. S. A.), 
With 9 figures. 
A study of the early embryology of Lepas fascicularis was 
undertaken in June 1894, at the suggestion of Prof. E. G. ConKLIN. 
The work was conducted during two summers (1894—95) in the 
laboratory of the U. S. Fish Commission at Wood’s Holl, Mass., and 
during the present year (1895—96) in the Zoological Laboratory of 
Northwestern University, under the direction first of Dr. ConkLin and 
later of Dr. WınLıam A. Locy. 
At the time the work was undertaken there was little literature 
on the early embryology of Lepas which followed recent lines of 
embryological research. After the work was well advanced there 
appeared an elaborate and important paper by Groom on the early 
development of certain Cirripedia (Phil. Trans., 1894). Groom’s paper 
records observations on the development of two species of Lepas 
(anatifera and pectinata), and of several species belonging to 
other genera. The observations on early stages had been completed, 
and most of the descriptive portion of this paper written before 
Groom’s paper could be obtained. Some of my independent results 
agree with those of Groom, and constitute new evidence confirming 
some of his observations. On the other hand, my observations lead 
to many interpretations widely different from those of Groom and the 
earlier workers on Cirripedes. 
Since the publication of the complete account of my observations 
must be deferred in order to study certain details of later development, 
and to complete comparisons with other species and genera, this 
preliminary note is offered. Merely an outline of the cleavage and 
germ-layer formation is given, since here my results differ most widely 
from those obtained by investigators of other Cirripedia. My observa- 
tions on the later development and discussions of the literature of 
the subject are reserved for the complete report. 
