94 



ERNEST WARREN. 



In B the diverticulum of tlie coelenteron (C.) is directly 

 comparable with the endodermal cavity of an ordinary 

 gonophore, the granular layer [g. e.) being equivalent to the 

 manubrial endoderm. Radial endodermal canals are not 

 represented. The cavity (c. 0.) around the outer surface 

 of the egg is the space between the manubrial endo- 

 derm and ectoderm ; the manubrial ectoderm [M. e.) in the 

 modified gonophore consists of a hemispherical layer of 

 cubical cells. The umbrella-cavity (c. U.) is a narrow slit-like 

 space. The outer ectoderm-lining (e. I. U.) to the umbrella- 



Text-fig. 4. 



Comparison of a typical gonophore (A) and the modified gonophore (B). 



cavity consists of a layer of fiat cells. Outside this ecto- 

 dermal lining of the umbrella there is a space {sp.) eqiiivalent 

 to the space between the umbrella-ectoderm and the outer 

 ectoderm layer of the gonophore. The outermost ectoderm 

 {e. I.) of a gonophore is indicated by a few flattened cells 

 adherent to the tall attenuated cells lining the upper portion 

 of the gonotheca. 



In fig. 7 of the Plate the gonangium is shown in vertical 

 section at right angles to the plane of flattening. The 

 terminal portion of the coelenteron of the blastostyle is seen 

 at C. and the out-pushing to form the spadix occurs at 

 d. G. 



The gonangium now grows to its full size, and the cells of 



