296 THE ZOOLOGIST. 



its upper edge was three and three-quarters of an inch from 

 the surface of the water. The second mass was laid, in another 

 part of the tank, on a little ledge of rock about three-quarters of 

 an inch from the surface.* 



It was pointed out above that the Gobies and Prawns did 

 not touch the eggs, but on February 8th (on the eleventh day 

 after laying) an Asterina gibbosa was observed upon the first 

 egg-mass, and another of these asteroids was found on it on the 

 9th. There is no doubt that one at least of the Asterina was 

 attempting to feed upon the eggs, because, when it was quickly 

 and gently lifted up, its stomach was found to be in the everted 

 condition. It seemed desirable to ascertain which animals in 

 the different aquaria would feed upon the eggs of the Bullhead, 

 and the following experiments were made, immediately before 

 the time of hatching of the eggs. 



A third Asterina, which was given a small group of the eggs, 

 fed upon them, but a fourth refused them. A hungry Common 

 Starfish (Asterias rubens) took them, but a recently fed indivi- 

 dual did not. Eggs thrown to six hungry Wrasse were seized 

 before they reached the bottom of the tank, "but all of them 

 were hastily disgorged again. f Three individuals of the Blenny 

 (Blennius pholis) treated the eggs in the same way. A Hermit- 

 Crab (Eupagurus bernhardus) would not touch them. A Long- 

 legged Spider-Crab (Stenorhynchus phalangium) picked up a 

 group of the eggs and held them to its mouth, but did not eat 

 them. Three females of the Four-horned Spider-Crab {Pisa 

 tetraodon) refused them. A large female Fifteen-spined Stickle- 

 back (Gasterosteus sjnnachia) followed and closely examined them 

 as they fell through the water, but did not take them into its 

 mouth. Four individuals of the Purple-tipped Sea-Urchin 

 (Echinus miliaris) certainly worked|upon two groups of the eggs 

 with their teeth, but it was difficult to see with what result. 



Two of the larvse of the Bullhead, on the second day after 

 hatching, were put into the aquarium containing the Fifteen- 

 spined Stickleback and were immediately swallowed by the latter. 



* Holt (op. cit. p. 27) mentions that at St. xindrew's eggs were frequently- 

 found on perpendicular ledges so as to be wholly or partially out of the 

 water at low tide. 



f The same Wrasse eagerly swallowed and retained eggs of the Common 

 Spider-Crab (Hyas araneus) about a week later. 



