80 THE ZOOLOGIST. 



Brittlestar (Ophiothrix fragilis), each of which was about four inches 

 in diameter, in a dredge on the coast of Essex. During the journey 

 to London in the collecting-can the Brittlestars amputated their 

 arms close to their discs. The mutilated Brittlestars were, however, 

 placed in an aquarium, as I had often been able to keep such injured 

 specimens during the regeneration of their arms. In the same 

 aquarium there were several examples of the Cushion- Star (Asterina 

 gibbosa), of about one and a quarter inches in diameter. On the 

 following morning (4th) I found that a Cushion- Star had enveloped 

 one of the Brittlestars in its arms, and on the 5th there was nothing 

 to be seen of the ophiuroid except fragments of skeleton. The 

 remaining two Brittlestars were destroyed by the Cushion-Stars 

 during the next two or three days. — H. N. Milligan. 



ANTHOZOA. 



Opelet Sea-Anemone Temporarily Attached to Shore-Crab. — On 

 November 13th I found that a Shore-Crab [Carcinus mce7ias) which 

 was confined in an aquarium with a number of examples of the 

 Opelet Sea-Anemone (Anthea cereiis) had one of the Sea-Anemones 

 attached to its abdomen. The Sea-Anemone measured about two 

 inches across its extended tentacles, and the Shore-Crab about six 

 inches across its extended legs. The Sea- Anemone was attached by 

 its base to the lower and hinder part of the abdomen in such a way 

 that its disc and tentacles dragged behind the Shore -Crab when the 

 latter walked on the floor. I do not know when the ccelenterate 

 attached itself, but it must have been at some time between the 

 afternoon of the 12th and 9.15 a.m. on the 13th. It was attached 

 with some firmness to the Shore-Crab, but it became detached from 

 the crustacean during a fight which the latter had with another 

 Shore-Crab at feeding time, about 9.30 a.m. It may reasonably be 

 conjectured that the Shore- Crab had sat for some time over the Sea 

 Anemone whilst the latter was attached to the rock by its tentacles 

 alone, its base being free and directed upwards, as occasionally 

 happens when the Sea- Anemones are moving from one place to 

 another. The Sea- Anemone had then attached itself by its base to 

 the motionless Shore-Crab, just as it would have attached its base 

 to another part of the rock. The Shore-Crab displayed no signs of 

 uneasiness in regard to its burden. This occurrence is interesting, 

 because it may perhaps illustrate one of the stages through which 

 such Sea-Anemones as Sagartia parasitica have passed in the course 

 of their evolution into commensal forms. — H. N. Milligan. 



