On the ' Porcupine ^-Expedition Madrcporaria. 289 



the varieties of shapes (some of ■which had been deemed of specific 

 value) which I had observed in the separate assemblages of specimens 

 from the Mediterranean, the Sicilian tertiaries, and the British and 

 Scottish seas. 



A perfect series of specimens from all these localities can be so 

 arranged as to show a gradual stnictural transition from form to 

 form ; so that the most diversely shaped Caryophyllun can be linked 

 together by intermediate shapes. The CaniophijlUa claims and 

 CnryophyUia cyathus can be united by intermediate forms, and all of 

 these to CaryophylUa Smithii and Caryophyllia lorealis. 



It is impossible to determine which is the oldest form ; but they all 

 apiK-ar to be reproduced by variation on some part of the area 

 tenanted by the section of the genus. The variability of the Caryo- 

 pthyllke of the Sicilian tertiary deposits is very marked ; and it is 

 equally so in the groups which live on disconnected spots in our 

 •waters. The Dingle-Bay series presents the greatc*st amount of 

 variability, and indeed is most instructive ; for by applving the 

 range of it to the classification of such genera as TrocJtocyathus and 

 MoiitUvaltia a great absorption of species must ensue. 



The Dingle-Bay CaryophylUfK are evidently the descendants of 

 those "which lived in the Western and Southern-European seas 

 before those great terrestrial elevarions took place which were con- 

 nected with the corresponding subsidence of the cireumiK>lar land 

 and the subsequent emigration of Arctic mollusca. They are not 

 closely aUied to the recent "NVc-st-Indian species ; buf they occupy a 

 position in the Coral-fauna representative of them. The same re- 

 mark holds good with reference to the affinities of the recent and the 

 cretaceous C'aryophyUice. They are not closely allied, and they 

 belong to different sections of the genus ; but they hold the same 

 posirions in the economy of the old and new distribution of animal 

 Ufe, and the recent forms are representative of the older. The 

 examination of the Dingle-Bay CaryophylUoi tends to prove that a 

 species is really the sum of the variations of a series of forms. 



A specimen was dredged np in 70-5 fathoms, temp. 42^-65 F., and 

 it exactly resembles forms which are frequently found in 90 fathoms, 

 and at a temp^erature slightly below that of the surface. M. Al- 

 phonse ililne- Edwards obtained some CaryopjTiylU(E from the cable 

 between Corsica and Algiers in 1110-1.550 fathoms. The bathy- 

 metrical range of these forms is therefore very grc at. I have placed 

 the species horealis in the first place, and regard the old species C 

 davus, C. Smithii, and Ccyathiis as varieties of it. 



Ceratocyathvs omntus, Seguenza. — A beautiful specimen of this 

 rare form was dredged up from a depth of 70-5 fathoms with some 

 Caryophyllias and a small Isis. The species is hitherto xinknown. 

 except in the Sicilian miocene*. 



Flahdlum hciniatum, Ed. & H. — This is the UlocyatTius aretian 

 of the late Prof. Sars. Many specimens were dredged up ; but most 



• Seguenza, " Disquisiz. Paleont. int. ai CoralL Foss.,"' Mem. della 

 Keale Accad. dell. Sci Torino, serie ii. tomo xxL 1804. 



