PLATE I. 



Ascopera gigantea, Herdman. 



Fig. 1. Ascopera gigantea, from the left side ; three-fourths of the natural size. 



Fig. 2. The neighbourhood of the oesophageal aperture, seen from the interior of tin 

 branchial sac, showing the aperture, the posterior end of the dorsal lamina, 

 and the (esophageal extremities of the fourteen branchial folds; natural size. 



Fig. 3. Dissection to show the course of the alimentary canal, seen from the right side, and 

 exposed by the removal of the mantle and the branchial sac, showing the 

 oesophagus, stomach, intestine, rectum, genital gland, and part of the muscula- 

 ture of the left side of the mantle ; natural size. 



