Plate XV. 

 {Top left) The pelagic mollusc Lnitliiim with its gas bubble float. 



Photograph by D. P. Wilson 

 {Top ri^lit) Goose barnacles, Lcpas, attached to a floating bottle. 



Photograph by D. P. Wilson 

 {Centre left) An oceanic polychaete worm Lugiscci. 



Photograph by Peter David 

 Three photographs of deep-sea squids by Peter David 



{Centre right) Calliteiitliis. 

 {Bottom left) Lirocraucliid. 

 {Bottom right) Pyroteiitiiis? 



