22 PROCEEDINGS OF THE 



o'assus. Neither will the entire reference of the phenomena now 

 under discussion to the severance of an auxiliary side-arm, and 

 consequent repair, stand, for, allowing that it may and does result 

 from this cause at times, I hope to show, later on, that the causes 

 are of a very much more varied description. 



1869. — An interesting and instructive paper by the late Mr. 

 John Rofe, entitled "Note on the Cause and Nature of the 

 Enlargement of some Crinoidal Columns," appeared during this 

 year.* In this paper Mr. Rofe conclusively showed that one 

 amongst the many causes of enlargement of Crinoid columns 

 arose from the attachment of a species of coral, Cladochonus crassus, 

 (M'Coy) and the subsequent endeavours of the Crinoid to envelope 

 its parasite (or epiphyte?) by the undue deposition of its substance. 

 He further demonstrated that in this process of envelopment "the 

 divisions of the ossicula of the column are carried round the 

 intruder and show on the outside." Very satisfactory figures 

 accompany this paper — one, f a cross section, showing the coral 

 and enclosing crinoidal matter, another, | a stem surrounded by a 

 Cladochonus, in which the substance of the stem has not yet 

 completely invested it. Mr. Rofe stated further, that a similar 

 enlargement in a Bradford clay Apiocrinites was caused by the 

 investment of a foreign substance. 



1876. — We next come to a paper read before your Society — 

 " Notes and Observations on Injured and Diseased Crinoids" (by a 

 "Corresponding Member ")§ — in which, as in the above paper, many 

 interesting facts are recorded, but scarcely bear out, I think, the 

 conclusions arrived at by the author, in their entirety. We are 

 indebted to a "Corresponding Member" for the results of a study 

 of numerous swollen stems from the Scotch Carboniferous rocks, 

 from which it appeal's specimens in all stages of injury and 

 repair were examined, from the much-mutilated condition of "two 

 flattened sides, each perforated," to one without " any evidence of 

 disease except the swelling of the column." The conclusions 

 obtained from the above facts, as stated by a " Corresponding 

 Member," appear to be (1) That the joints or ossicles of the column 

 are thickened, producing an elongation of the stem, and a modifi- 

 cation of the surface ornamentation; (2) a straining of the parts 



* Oeol. Mag., VI., 1869, p. 351. + P. 352, f. 3. % Ibid., f. 2. 



§Proc. Nat. Hist. Snc. Glasgow, 1876, III., pt. 1, p. 91. 



