SPIRIFERA. 37 



by far the deepest. The lateral portions of the shell are regularly curved, forming, with 

 the extremities of the hinge-line, acute, but not prolonged cardinal extremities ; area large, 

 triangular, more or less elevated, and divided by a fissure of moderate width. Beak small, 

 not much produced above or beyond the level of the area. The mesial fold in the dorsal 

 valve is broad, and more or less elevated, without ribs, and corresponding with a deep and 

 rather wide longitudinal sinus in the ventral one. Each valve is ornamented by about 

 twenty or twenty-two narrow radiating ribs, intersected by closely disposed, sharp, con- 

 centric, undulating laminae. The measurements from two examples have produced — 



Length 12, width 21, depth 10 lines. 

 8, „ 11, „ 6| lines. 



06s. This beautiful shell was correctly described and illustrated by Professor De 

 Koninck in 1843, but unfortunately under the mistaken denomination of Sp. hystericus, 

 but which the same author replaced by that of S. tricornis in 1851. It had, however, 

 been named Sp. laminosa, in 1844, by Professor M'Coy, a denomination we are bound to 

 maintain ; notwithstanding that the term is in itself hardly appropriate, from the fact that 

 several other Carboniferous, Devonian, Silurian, and even Permian species, are similarly 

 ornamented by scale-like imbricated laminae. The illustrations of this shell, published in 

 the ' Synopsis,' are so incomplete and unsatisfactory, that we can easily understand the 

 doubts entertained by some of those who have not, like ourselves, had the opportunity of 

 studying the Irish specimens ; and I feel at a loss to divine the reason which could have 

 tempted Professor M'Coy to place this and several other species into the sub-genus Cyrtia, 

 with which it and they possess so little affinity. Sp. laminosa has some points of 

 resemblance to Spiriferina octoplicata ; but it is readily distinguished by the greater 

 number of its ribs. 



In our British localities the shell under description is more often found with its valves 

 disunited ; the mesial fold not extending, in general, beyond the level of the lateral portions 

 of the valve ; but in some exceptional examples preserved in the Cambridge Museum, this 

 portion of the shell "is produced in front into a long tongue-shaped flattened lobe" (figs. 

 21, 22), as was observed by Professor M'Coy in his work on 'British Palaeozoic Fossils.' 

 The specimens described in the • Synopsis' under the name of Sp. speciosa undoubtedly 

 belong to Sp. laminosa, an opinion in which Mr. Salter fully concurs. 



Loc. It is stated by Professor M'Coy not to be uncommon in Derbyshire ; Mr. Tate has 

 the shell from Denwick, Northumberland ; Mr. Howse from Redesdale. In Ireland it is said 

 to occur at Stridagh Point, Malahide, Hook, Abbey Bay, Ballintrillic, and Ballyshanns, from 

 most of which localities I have been able to examine examples, through the kindness of 

 Dr. Griffith. It is not rare at Tournay ; and has been found, although less commonly, at 

 Vise and in other Belgian localities, by Professor De Koninck. 



