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



grow upon. This decided, I returned to the sponge theory, 

 which again was not satisfactory, as the fibre of Luffaria^ 

 which of all other spongeous ones comes nearest in structure 

 to that of Parkeria, is hollow, and not solid as in the recent 

 Hjdractiniidae that I had described in the ' Annals ' of 1873 

 {I. c.) ; and recognizing the identity in form between the fos- 

 silized fibre of Parkeria and the recent fibre of the Hydrac- 

 tiniidee, especially of Chitina ericopsis^ in which some of the 

 stems are an inch in diameter, and the whole bush-like ske- 

 leton, branches, hydrotliecai, and every thing else elaborated 

 out of a mass of uniformly anastomosing, reticulated, chiti- 

 nous fibre without core or cortex, I immediately inferred that 

 Parkeria had been closely allied to, if not a species of Hydrac- 

 tinia. 



Still to further confirm the inference, I examined the speci- 

 mens of Parkeria and Lqftusia at the British Museum, and 

 those of Parkeria and Hydractinia pliocena (Allman) at the 

 Museum of the Royal School of Mines, through the kind aid 

 respectively of Messrs. H. Woodward and E. T. Newton ; 

 after which I obtained an excellent specimen of Hydractinia 

 pliocena from Mr. Ed. Charlesworth, of the Strand, to which 

 I must now add specimens of a recent calcareous Hydractinia 

 from Cape Palmas, on the Guinea coast of Africa, that were 

 sent to me some time ago by my friend Mr. T. Higgin, of 

 Liverpool. 



Thus prepared for tracing the resemblance of the recent 

 HydractiniidEe through the fossil species H. pliocena to Par- 

 keria^ and thence to the Stromatopora — it is desirable that I 

 should premise a description of the development of the chiti- 

 nous-fibred skeleton of //. echinata, as well as that of the 

 skeleton or polypidom of the calcareous species from Cape 

 Palmas, in order that I may be the better able to illustrate the 

 fossilized from the recent structure. But as the development 

 of the former has already been represented in the ' Annals ' 

 [l. c), I must refer the reader to the figures there given for 

 this part of my communication. 



Beginning with Hydractinia echinata, and taking for exa- 

 mination a portion of the earliest or first-formed layer (which 

 will be henceforth termed "lamina") of the skeleton as it 

 exists on the inner side of a Buccinum bearing this Hydrozoon, 

 where it is almost immeasurably thin, but may be obtained by 

 dissolving away the shell with acid and floating the lamina on 

 to the surface of a slide, for placing it under the microscope — • 

 it may be observed, when viewed with an inch compound 

 power, to consist of a branched, anastomosing, coenosarcal 

 stolon-tubulation, forming a network in which the interstices 



