2G6 PROCEEDINGS OF THE 



having had articulated spines never entered into the minds of any 

 one to whom I ever submitted this coral, nor have I ever seen a 

 single specimen which, on close examination, represents such an 

 appearance, or that would warrant the conclusions of Dr Duncan. 



There are two other points to which I wish to call your atten- 

 tion, beyond what has been already stated in the remarks and 

 correspondence. The first is one which appears to me to go hard 

 against the supposition that the booklets were ever articulated 

 upon tubercles by any ligamentary process. The fact stands thus: 

 all the specimens of this coral are found in marine limestone 

 shales, associated with a great many genera and species of organic 

 remains, consisting of corals, crinoids, echini, mollusca, etc. These 

 all bear evidence of having lain for some time upon the sea-bottom 

 after the death of the organisms, during which the ligaments that 

 held them together had in most cases gone to decay, and allowed 

 their parts to be scattered about by the waves and currents, before 

 becoming embedded in the mud in which we now find them. If 

 this has been the case with large organisms boun'd together with 

 strong ligaments, we would hardly expect that those which are 

 said to have attached these delicate booklets to the stem of the 

 coral Avould have remained uninjured. Indeed, if they had ever 

 been articulated, I would have considered it one of the rarest 

 things to have found a specimen of the coral with the booklets 

 attached, as rare as what it is to find in the same strata, any of 

 tlie remains of the crinoids, echini, or chitons, with their parts 

 preserved in their relative positions. But if the booklets are 

 viewed as solid processes upon the stem of the corallum, we can 

 then easily perceive how they may have been preserved in most 

 instances after the death of the organism, their present fractured 

 state being the result of the pressure they have sustained while 

 lying embedded in the shale. 



The second point to which I wish to make reference before 

 closing this paper, is that Dr Duncan in his description of H. Lyelli 

 makes no mention whatever of that species having borne booklets 

 upon the costae. He only states that it was marked with occasional 

 tubercles, but makes no inference as to what could have been their 

 use. I thhik that every one who examines the specimens upon 

 the table will admit that the largest diameters of the corallum as 

 well as the smallest, bore these booklets; also, that the so-called 



