164 DEVONIAN FAUNA. 



seems best to assign the position of type to his var. y, which is represented by 

 his figures 36 a and b. To the species thus restricted may safely be referred a 

 Lummaton form with which his description fairly corresponds. 



At the same time his definition of both species is too slight to be satisfactory ; 

 and, even after the examination of his type specimens, some doubt may remain 

 about their proper identification and limits. 



Lonsdale's figures and description 1 of F. antiqua? from Devonshire are quite 

 unidentifiable, and probably include several species without distinction. 



Lastly, M'Coy, 2 leaving F. antiqua, Goldfuss, as the name of the species from 

 the Plymouth Limestone, separates the South Petherwyn and Carboniferous 

 specimens under the name of F. plebeia, M'Coy. 



On the whole it appears probable that there was no real ground for identifying 

 any of these British fossils with those described by Goldfuss. 



It will be seen further on that several fresh species must be added to the 

 Devonian list. The material at my disposal has been insufficient to permit very 

 satisfactory conclusions in some cases ; but it is evident not only that the number 

 of species of Fenestella must be increased, but that there are interesting evidences 

 of several other genera. Even where these evidences are too meagre for the full 

 description of a species, they suffice to indicate its existence. 



In my attempts to decipher these fossils I have to acknowledge the very great 

 kindness of Dr. J. W. Gregory, without whose frequent help I could not have got 

 even so far towards their interpretation as I have been able to do. The trans- 

 parent sections which have been very kindly prepared for me by Mr. F. Chapman 

 have also thrown light on many points of structure which would otherwise have 

 been unattainable. I have followed Ulrich in his classification and generic 

 definitions. 



1. Order.— GYMNOL^EMATA, Allman, 1856. 



1. Sub-order.— CRYPTOSTOMATA, Vine, 1883. 



Zoarium, either bifoliate, or arranged in single layers forming fenestrated 

 expansions, or ramose with the zocecia arising from a real, or imaginary, axis. 

 Primitive cell generally with the orifice produced into a tubular shaft or vestibule. 



I. Family. — Fenestellid^e, King, 1849. 



Zoarium forming rigid reticulate expansions, celluliferous on one side, consisting 



of branches generally either united by dissepiments or anastomosing. Primitive 



1 Is 10, Lonsdale, ' Geol. Trans.,' ser. 2, vol. v, pt. 3, pi. lviii, figs. 10—10 6. 

 L851, M'Coy, ' lint. Pal. Koss.,' p. 75. 



