3G r. H. CARPENTER ON COMATULiE TROM 



5. Oh some undescrihed Comatul^ from the British Secondary 

 EocKS. By P. Herbert Carpenter, M.A., Assistant Master at 

 Eton College. (Bead December 3, 1879). 



(Communicated by Prof. P. M. Duncan, F.E.S., F.G.S., &c.) 



[Plate V.] 



My work on tbe Comatulce of the * Challenger ' Expedition naturally 

 led mo to a consideration of their fossil representatives ; and I 

 found that although continental palaeontologists have described 

 several species from the Jurassic and Cretaceous rocks of Central 

 Europe, hardly one has been recorded as occurring in the corre- 

 sponding formations of the British area. It soon appeared, however, 

 that this is not because we have none to record, but merely because 

 neither descriptions nor names have been given for those which we 

 have. In the following pages I propose to make good this defi- 

 ciency ; but I would first express my sincere thanks to Mr. 

 Etheridge, of the Eoyal School of Mines, to Professor Hughes, of 

 Cambridge, and to Messrs. Henry Woodward and B. Etheridge, jun., 

 of the British Museum, for the ready kindness with which they have 

 allowed me to make use of specimens in the collections under their 

 charge. I am also greatly indebted to Dr. Wright, of Cheltenham, 

 for placing at my disposal two specimens from his own collection. 



Schliiter * has recently published some descriptions, together with 

 excellent figures, of several new fossil Comatulce from Germany, 

 Italy, and Sweden. At the same time he has expressed some views 

 as to their anatomy and classification which are inconsistent with 

 some of his statements of fact, and still more so with the results of 

 my own observations on the anatomy of the recent species. 



He gives the following general description f of the "Knopf" or 

 centrodorsal piece, which is the part of the skeleton that is most 

 usually found fossil, frequently being the only part preserved : — 



** Besides the central pit lodging the heart or chambered organ 



many species have five other smaller pits, disposed radially aroimd the central 

 one. These radial pits, as shown by Greeff for Antedon europcsus {Comatula 

 mediterranea) and byLudwig for A. rosaceus, are blind saccular extensions 

 of the body-cavity, which penetrate into the apical skeleton, but contain 

 no special organs in the mature animal. In several (fossil) species there is a 

 stellate depression on the underside of the centrodorsal. Each ray of this star 

 corresponds with one of the radial pits, which become narrower from above 

 downwards. The inner part of the star is filled up with calcareous deposit, as 

 a consequence of which the radial pits are also closed below." 



There are several points to be noticed in the above description. 

 In the first place, Schliiter is hardly correct in saying that " many 

 species " have radial pits. It is true that they occur in six out of the 

 eleven fossil species mentioned by him (including Glenotremites 



* " Ueber einige astylide Crinoiden," Zeitschr. der deutschen geolog. 

 Gesellsch. Jahrgang 1878, pp. 28-66, Taf. i.-iv. 

 t Op. cit. p. 33. 



