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bases of the arms, so that we get exactly the same appearance 

 as that described above for the curious rnutilated annimals. 



Now of course the first thought would be, that the damage 

 was occasioned by the capture or afterwards by bad preservation. 

 But this cannot be , as I have dredged all the examples myself, 

 taken them carefully out of the thick mud in which they live, 

 with unbroken arms and kept them alive for weeks in my aqua- 

 rium. I sometimes caught the sound ones along with the forms 

 without the dorsal covering, but it is certainly curious, that 

 the examples without covering seem to be by far more abundant 

 than the sound ones. 



During the last few days I have examined a collection of Ophiurids, 

 collected by Mr. J. Versluys, during an expedition of the Count 

 Dalmas in the West-Indies. To my great satisfaction I found amongst 

 these some animals, that correspond very well with the examples 

 described by Jeffrey Bell, but fortunately I found also some 

 specimens with the dorsal disk-covering, which belonged un- 

 doubtedly to the same species. The supposition of Jeffrey Bell, 

 that the animals should belong probably to Ophionema or Oplii- 

 onephthys, proves hereby not to hold good, as they belong to the 

 genus Amphiura and seem to be identical with, or at least very 

 nearly allied to Amphiura grisea , Lym. By removing the disk 

 covering I could again produce the same condition as in my 

 East-Indian specimens. 



Amongst these West-Indian forms I found however at last also 

 some disjoined disks with the genital pouches, which were quite 

 filled up with eggs or spermatozoa. With the disk covering 

 the long genital plates were also removed, while the disk covering 

 had contracted itself ventrally so as to form an almost closed 

 sac filled with the genital products. 



Now, especially from my experience in the Bay of Batavia I 

 cannot but believe, that the loss of the disk-covering is a 

 normal function in the life history of the Ophiocnida echinata, 

 probably periodically repeated at fixed times. It seems moreover 

 probable, that this loss of the disk-covering depends upon the 



