44 Mr. H. J. Carter on the close Relationship of 



TriiwutiiUna refuh/ens, iroiitfort. llaro. 



tiibcrosa, Fichtel & Moll. Common — the form named by 



D'Orbigny Tr. vut'labilis, of which Soldani gives no less than 



284 figures in the ' Testaceographia,' the better to illustrate its 



wonderful range of variation, 

 PulvinuUna concent rica, Parker & Jones. Rare. 



vermuiJata, D'Orbiguy. Very common. 



Eotalin Beccani, Linne. Common, specimens large. 



Tinojiorits t(svis, Parker & Jones. Hare. 



Polytrema mininceiun, Linne. Common, some of the specimens 



growing on Nubecidarite. 

 Nonioniiia usterizans, Fichtel & Moll. Rare. 



dcpressuJa, Walker & Jacob. Rare. 



Polystoviella crisjia, Linno. Common. 



IV. — On the close Relationship of Hjdractinia, Parkeria, 

 and Stromatopora ; icith Descriptions of new SjJecies of the 

 former J both Recent and Fossil. By H. J. Carter, F.R.S. 



[Plate VIII.] 



In limine, it may be obsei-ved that an intimate knowledge of 

 the structure of the skeleton of Hydractinia is absolutely 

 necessary to ti-ace the chain of resemblances that exists 

 between it and Stromatopora through Parkeria^ not less a 

 perusal of the facts as they are consecutively given in this 

 contribution, and, if possible, the presence of the objects them- 

 selves. 



Having had to study carefully the homy chitinous skeleton, 

 whicli is the most imperishable part of the Hydractiniidse, in 

 order to write and illustrate a paper on several recent species 

 (Ann. & Mag. Nat. Hist. 1873, vol. xi. p. 1, pi. i.), I am 

 not the less able to see the resemblance that exists between 

 them and those of bygone ages whose skeletons alone are 

 handed down to us in a lapidified state ; and hence it was 

 announced that Parkeria had been inferred to be one of these 

 (Ann. & Mag. Nat. Hist. 1876, vol. xviii. p. 187). I was 

 not aware then that species of Stromatopora^ even as far back 

 as the Devonian and Silurian systems respectively, would 

 have to fall into the same category ; so what I have to state of 

 these will appear in the sequel. 



All who have studied Parkeria must be aware that it has 

 been well described and illustrated by Dr. Carpenter (Phil. 

 Trans. 1870, vol. 159. pt. 2, p. 721, pis. 72-76) ; next to which 

 follows Loftusia^ equally well described and illustrated by Mr. 

 II. B. Brady [ihid. pis. 77-80). 



