82 THE ZOOLOGIST. 



food ; (2) vegetable matter as food ; (3) inorganic matter as 

 food ; (4) the search for food ; (5) the positions and postures 

 adopted in feeding ; and (6) the time spent in feeding. 



1. Animal Matter as Food. 



Chordata. — Eichelbaum found remains of the ascidian Cynthia 

 in one, and probably in two, of the eleven Sea-Urchins which he 

 examined. 



A Sea-Urchin, 23 mm. in diameter, was observed by me to 

 devour part of an Ascidia sp. of 30 mm. in length. The species 

 of fishes which have died in the aquaria and have been wholly or 

 partially devoured by the Sea-Urchins are the Striped Wrasse 

 {Labrus mixtus), Common Goby {Gobius paganellus), Gattorugine 

 Blenny {Blennius gattorugine), and Plaice {Pleuronectes platessa). 

 The fins, flesh, and viscera of the fishes have been eaten, but 

 the bones have usually been neglected. A Sea-Urchin, however, 

 which was given a small mass of bone from the skull of a 

 Gattorugine Blenny, the flesh of which had been scraped away by 

 other echinoids, ate a portion of it. In has already been recorded 

 in * The Zoologist ' that four Sea-Urchins were seen to work 

 with their teeth upon two groups of eggs laid by a Sea-Bullhead 

 {Cottus bubalis), though with what result it was difficult to see.* 

 Baw beef is eaten with avidity. The Purple-tipped Sea-Urchin 

 would probably eat any dead marine chordate, or even any 

 dying chordate which it could attack with success. 



If the Sea-Urchin can once obtain a grasp of a small dying 

 fish, it holds the fish tenaciously, as is exemplified by the following 

 incident. t A Striped Wrasse of 40 mm. in length, which was 

 thought to be dead, was removed from an aquarium in order 

 that it might be used as food for the Sea-Urchins. When, 

 however, the tail of the fish was thrust beneath the body of one 

 of the Sea-Urchins, 38 mm. in diameter, which was clinging to 

 the vertical side of the aquarium, the fish suddenly began to 



* H. N. Milligan, " Notes on the Eggs and Larvae of a Sea-Bullhead 

 {Cottus bubalis),'' ' Zoologist,' vol. xix, 4th ser., 1915, pp. 292-6. 



f I have not been able to find any previous record of this Sea-Urchin 

 deliberately holding prey with its spines, but H. Eisig (" Biologische Studien 

 angestellt in der Zoologischen Station in Neapel," ' Kosmos,' vol. xiii, 1883, 

 p. 128), mentions that an Echinus (Strongylocentrotus) lividus held a w^orm 

 ■with the points of its spines. 



