20 PROCEEDINGS OF THE 



this branch of study, whether having reference to Carboniferous 

 species or those met with in younger rocks. 



17D3. — One, the first to notice these injured Crinoid stems, the 

 Rev. David Ure, in speaking* of the Crinoidal remains collected by 

 himself in the Rutherglen neighbourhood, says, "Some" (i.e., the 

 stems) " appear to have been wounded in a recent state. This is 

 indicated by an unusual swelling, which in every case exhibits a 

 large and deep puncture, probably the cause of the swelling." This 

 notice is accompanied by a figure representingt a portion of a 

 column, irregularly swollen, and towards one side a laterally elon- 

 gated puncture. Ure's figure may be taken as a typical example 

 of this condition of stem amongst Carboniferous Crinoids. 



1820. — Baron Yon Schlotheim gave a figure of a portion of the 



stem and calyx of the characteristic secondary Eucrhiites mesioili- 



formis,\ the Bradford Encrinite of Parkinson. In this case the 



column is regularly and gradually swollen, but there is no evidence 



of any injury or puncture. 



1821. — Mr. J. S. Miller, in his Natural History of the 

 Crinoidea^ enters on the present subject somewhat fully. He gives 

 a good figure || of an enlargement of the stem of the common Car- 

 boniferous Crinoid, Poteriocrinus crassus, and ascribes it to a rapid 

 secretion by the animal to repair an injury sustained through the 

 loss of a side-arm. He says: "Its column has sometimes numerous 

 joints swelling gradually out, and thus giving it a barrel-shaped 

 appearance, generally pressed in on one of its sides, and becoming 

 there concave, with a central perforation, evidently leading to the 

 alimentary canal. This has all the appearance of a cicatrized 

 wound, and as the alimentary canal in the column is not increased, 

 the swelling can only arise from a more rapid secretion from these 

 joints, probably to strengthen it, and to compensate thus for the 

 injury probably sustained in one of its auxiliary side-arms. The 

 cavity before mentioned was probably produced by the loss or 

 separation of the injured auxiliary side-arm from the column, and 

 the subsequent cicatrizing of the wound. ^[ In addition to this 

 illustration, Miller also gave figures of a peculiar condition in the 

 stem of Actinocrinus dactylus** " The column sometimes exhibits 



* The History of Rutherglen and East Kilbride, 1793, p. 324. 



+ T. 18, f. 1. %Die Petrefactenhuide, 1820, atlas, t. 29, f. 5. 



§ Bristol, 4to, 1821. || Plate facing p. G8, p. 18. 



IT hoe. cit., p. 69. ** Actinocrinus, t. 6, f. 17 and 18. 



