DTTBLIW NATUBAL HISTORY 80CIETT. 77 



Fbofessor J. R. KiNAHAN next exhibited specimens illustrative of — 



BEMARXS ON THE ZOE OF EIJRYNOME ASPERA, AND THE HABITS OP THE 

 ANIMAL IN CONFINEMENT. 



The passage of the majority of the higher Crustacea through the zoe state 

 is now a recognised fact in Zoolog}', and fresh species are turning up 

 almost daily as zoes. That which is exhibited to-night is an example 

 of this, as the zoe of any of the Lambridaa, as far as I know, has never 

 been described. 



The specimens from whence the ova were obtained were captured 

 during one of the minor excursions of the British Association, in a dredg- 

 ing party, formed through the kindness and liberality of that well-known 

 and indefatigable naturalist, Robert M 'Andrew, Esq., consisting of Pro- 

 fessors Allman, Archer, Redfem, Rev. P. Carpenter, of Warrington, 

 Robert M* Andrew, Esq., and son. Dr. Edwards, ifr. Hyndman, and my- 

 self. The scene of our labours was the Kish Bank, where, in addition 

 to many other Crustacea, five specimens of ^. aspera were obtained, two 

 of them loaded with spawn. 



These I placed in a small salt-water tank, changing the water occa- 

 sionally. They were first placed in the tank on the 1st of September; 

 the ova then being of a bright salmon colour. On the 7th I found that 

 the ova in one of them had become much darker, being a dirty drab 

 colour under the microscope, but little change could be detected in the 

 appearance of their contents. On the 10th the ova were a much darker 

 drab, and the black eyes of the zoes plainly distinguishable to the naked 

 eye. The parent had all this time most assiduously kept up a perpetual 

 current around and through the ova, seemingly by means of the pedi- 

 palps, at the same time keeping the mass in constant vibration by rhyth- 

 mical up-and-do^vn motions of the abdominal false feet, to which the 

 ova were attached. She also sought the sunny side of the tank more 

 than her wont now is. On the evening of the 12th the zoes could be 

 distinguished coiled up in the ova, fully formed, and the motions for 

 aeration were very vigorously carried on ; and on examining the tank 

 on the morning of the 13th I found it completely filled with many thou- 

 sands of zoes, which kept together in one continuous swarm at the side 

 nearest the light. These gradually increased in size, and also altered 

 in their form, seeming so active and healthy that I was in hopes I 

 might have been able to trace their complete changes; but unfortunately 

 the second specimen of E. aspera died on the evening of the 1 7th, poi- 

 soning the tank, so that on the morning of the 20th I found my poor 

 zoes dead, putting a stop to experiments as far as they were con- 

 cerned. 



The parent crab, however, still continues in health and vigour, al- 

 though the water has not been changed till to-day for the last six weeks, 

 and does not now consist of more than two pints in a circular tank, six 

 inches in diameter, and although two green crabs, C. manaSf during the 

 time died from the poisonous eflfccts of impure water. Its habits are inte- 

 resting ; it is but a sedentary animal ; it seeks the light occasionally^ 

 generally, however, keeping to the shadiest part of the tank. At night it 



