REPORT ON THE DEEP-SEA MEDUSAE. 



143 



GLOSSAKY. 



A. ACTINOSTOMA. 



Mouth. 



MuND. 



a Osculum. Central aperture. Osculum. 



Month opening of the Medusse, derived from the primitive mouth (the archistome 

 or blastopore of the gastrula) ; its margin forms the bounding line between the inner and 

 outer germinal layers (endoderm and ectoderm) ; the inner (axial) surface of the oeso- 

 phagus is covered with endoderm ; the outer (abaxial) with ectoderm. 



B. Burs.®. Pouches. Taschen. 



h Bursal gastroeanales. Chymiferoiis pouches. Geflisstaschen. 



Broad, fiat, pouch-shaped hollow spaces of the gastrovascular system, lined with 

 endoderm ; partly direct radial diverticula of the central gastral cavity, partly peripheric 

 expansions of different parts. 



