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XXL — The Structure of Turrilepas Peachi and its Allies. By F. R. Cowper Reed, 

 M.A., F.G.S. Communicated by Dr Horne, F.RS. (With a Plate.) 



(MS. received July 18, 1908. Read July 20, 1908. Issued separately December 24, 1908.) 



Having had the privilege of examining the type specimens of Turrilepas scotica, 

 Etheridge jun., # and T. Peachi, Etheridge jun. and Nicholson, t in Mrs Gray's 

 collection, and in addition to them a large number of examples of the genus recently 

 collected by Mrs Gray from the Girvan area, as well as many specimens in the Sedgwick 

 Museum, Cambridge, from several horizons in the Haverfordwest district and from the 

 Dufton Shales near Melmerby and from Bala beds of other localities, some important 

 new features have been recognised in these curious fossils which help to throw light on 

 their structure and relations. 



Clarke | discussed in 1896 the relations of the genera Turrilepas ( = Plumulites), 

 Lepidocoleus and Strobilepis, but made no mention of these Scotch species of Turrilepas 

 which differ in a marked way from T. Wrightii (De Koninck), which is the type of the 

 genus. The latter species was described by Dr Henry Woodward in 1865,§ and is 

 from the Wenlock beds of Dudley. 



Ruedemann II has more recently given an account of the Trenton species, Lepidocoleus 

 Jamesi, Hall and Whitfield, and has made some suggestive remarks on the associated 

 narrow leaf-shaped plates. 



In the case of the British examples of Turrilepas it is unfortunate that the speci- 

 mens in nearly all cases consist of isolated plates, but amongst Mrs Gray's new material 

 there is one nearly complete individual (Plate, fig. 1) from the Starfish bed with the 

 plates in position, and it closely resembles the form described and figured by Barrande 

 as Plumulites folliculum from Stage Dd 2 . Though its state of preservation leaves some- 

 thing to be desired, yet it affords important evidence as to the relation of the separate 

 plates and the general structure of the fossil, and indeed casts doubt on the view that 

 Plumulites, Barrande, and Turril&pas, Woodward (type T. Wrightii) are synonymous. 



Before proceeding to describe this specimen a few remarks may be made on the 

 character and structure of the separate plates of T. Peachi, and on the specimens 

 previously described by Etheridge and Nicholson. These authors described the kite- 

 shaped plates as possessing a "strong, narrow median keel." From an examination of 



* Etheridge jun., Proc. R. Phys. Soc. Edin., 1878, iv. p. 166, pi. ii., figs. 1, 2 ; Etheridge and Nicholson, 

 Mon. Silur. Foss. Girvan, fasc. ii., 1880, p. 214, pi. xiv., figs. 22-27. 



t Etheridge and Nicholson, Mon. Silur. Foss. Girvan, fasc. iii., 1880, p. 301, pi. xx., figs. 8-10. 



X Clarke, Amer. Geol, xvii., 1896, pp. 137-143, pi. vii. 



§ Woodward, Quart. Journ. Geol. Soc, xxi., 1865, p. 486, pi. xiv., figs, la-ll. 



|| Ruedemann, Bull. 49 New York State Mus., 1901, p. 87, pi. 4, figs. 16-19. 



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