SPAWN OF DORIS. 13 



out, tlioiigli tliey occasionally floated at the surface 

 by means of the expanded foot, back-downward. 



Polycera ocellata on the other hand is fond of 

 coming out of the water, and of remaining at the 

 edge of the vessel, when it looks like a little ball of 

 olive-coloured jelly. It frequently floats by the 

 foot, and is capable of a slow progression in this 

 manner. If pushed under water, it retracts its bran- 

 chiae and tentacles, incurves the edges of the foot, 

 and sinks rapidly to the bottom ; but soon recovers 

 its equanimity, and crawls up to the summit of the 

 nearest sea-weed, or up the sides of the reservoir to 

 the surface again. 



Doris tuherculata slowly glides round and round 

 the vessel just beneath the surface, now and then 

 lifting and puckering up the edge of the cloak, and 

 allowing the air to bathe the body. 



Doris hilamellata, of which there were three in the 

 vessel, was very social in confinement, continually 

 finding out one another, and crowding close up toge- 

 ther. They crawl round the pan, generally resting 

 close to the surface, often with the mantle a little 

 raised, so that the air may reach the body. 



Feb. 22nd. — The Doris hilamellata laid a ribbon 

 of spawn attached to the side of the pan almost at 

 the surface of the water. It adhered bv one edo^e 

 and formed an imperfect spire or cup, the ribbon 

 being bent upon itself; the upper edge or brim 

 leaning a little outward, and being puckered. The 

 general substance is white and opaque, owing to a 

 vast number of minute eggs, enveloped in a clear 

 jelly. The colour therefore appears uniform except 



c 



