the Genus Fistulipora, M^ Coy. 505 



as Ceramopora^ Hall, we should not for that reason adjudge 

 the evidence as to its zoological position derived from its 

 adult characters to be in any way invalidated. All that we 

 should feel inclined to say would be that, in the case sup- 

 posed, Fistulipora incrustans passed through a ^' Ceramo- 

 poroid stage " or a " Polyzoan stage," in precisely the same 

 way that a Brachiopod may pass through an Annelidan stage 

 in its development, and yet may not become an Annelid. 

 As a matter of fact, however, we do not admit that Fistu- 

 lipora incrustans was at any period of its growth a Ceramo- 

 pora^ or, indeed, in any way essentially different from what it 

 became when fully matured. On the contrary, thin sections 

 of the youngest specimens which we have been able to 

 examine show an internal structure in all respects precisely 

 similar to that exhibited by adult specimens. All that we 

 can admit is that in its early condition of a very thin invest- 

 ing crust Fistulipora incrustans may have the general aspect 

 of a Polyzoan ; but here the resemblance ceases, and its inti- 

 mate structure shows no indication of any alliance with the 

 Polyzoa. 



We think that from the evidence we have brought forward 

 there is now good ground for assigning to the genus Fistu- 

 liportty M'Coy, a place among the Actinozoa, and probably in 

 that division of it known as the Alcyonaria. 



Formation and Locality. Fistulipora incrustans^ PhilL, is 

 found in the Carboniferous Limestone, Bolland, Yorkshire 

 [Phillips) ; Derbyshire and Ireland {M^ Goy) . Also in the 

 Carboniferous rocks of Redesdale, Northumberland, where it 

 is common, and in the west of Scotland {John Young). 



Fistulipora muscosa^ Nich. & Foord. 

 (PI. XV. figs. 3, 3 a.) 



Fistulipora minor, Nicholson, Pal. Tab. Corals, p. 306,' fig. 39 (1879) 

 [non Fistulipora minor, M'Ooy]. 



Spec, cha/r. Corallum forming thin irregular crusts, more 

 or less extensively attached to foreign bodies. Autopores 

 in the main oval, but commonly showing the trifoliate form 

 characteristic of the genus. The autopores are rather less 

 than half a millim. in diameter, about three of them occupying 

 a space of 2 millim. ( = about thirty-six in the space of an 

 inch). The mesopores are angular and of variable size, two 

 rows usually intervening between any given pair of autopores. 

 The walls of the mesopores are very incompletely developed, 

 and the close-set tabulae coalesce to form a vesicular tissue. 



