74 ECHINODEEMATA. 



that specimens procured in 1833 were pure white, whereas most of those 

 obtained in 1841 were yellowish-brown. The animal dwells in the 

 jBstuary of the Forth, from the island of Inchkeith down to the Mar 

 Bank, fifty or sixty miles farther distant. 



Although this animal is distinguished by few peculiarities, perhaps 

 from my failing to investigate its nature sufficiently, it exhibits one of 

 the most remarkable kind, in the spontaneous subdivision of the body 

 into two or even a greater number of parts. Neither does this violent 

 effort, as it might appear, prove fatal to the specimen, for the defective 

 organs are regenerated complete in each of the portions, renovating them 

 to entire animals. 



So singular a process being incident to all, it becomes difficult to 

 fix the ultimate dimensions to be acquired by individuals. 



Of two specimens, one large and the other small, obtained from the 

 Mar Bank, one solved the problem, so long obscure, as to the mode of 

 progression, by traversing the inner circumference of a vessel four inches 

 wide within two hours, having the tentacula displayed in front as it 

 advanced. Both were active. While at rest they adhered by their 

 peduncles or suckers to the glass, near the surface of the water. 



The larger exceeded the smaller by a third part. On June 28th it 

 ruptured asunder into nearly equal halves, as appearing figs. 10, 11, and 

 remaining so during an indispensable absence, until my return on August 

 second ; they appeared on the 29th as in figs. 12, 13. On August second 

 I found the smaller had also ruptured in halves, which now appeared 

 as in figs. 14, 15. 



After the lapse of three or four weeks I witnessed, with considerable 

 sui-prise, the regeneration of a complete arborescent funnel in each poste- 

 rior half of the two specimens. But the animals were now so shy that 

 it was difficult to obtain a view either of these or of the original tentacula 

 of the anterior portions. Nevertheless the regenerations were ascertained 

 to be very short and very white. 



All four parts of the two Holothurige moved about in the vessel. 

 The tentacula of the whole four were displayed on the 30th of August, 

 but their impatience of Ught had not abated. 



