Plate 4. 



All figures from unretouched photographs of preserved specimens. 



Fig. 1. Olindias singularis. X 2. 



Fig. 2. Liriope tetraphylla, young specimen 4 mm. in diameter, before appearance of 

 gonads. 



Fig. 3. Liriope tetraphylla, older individual 7 mm. in diameter; gonads are broad — oval 

 or squarish. 



Fig. 4. Aequorea coerulesceus, specimen 45 mm. in diameter ; oral view, showing particu- 

 larly the condition of the lower gastric wall, and the numerical relation of radial 

 canals to tentacles. 



