SPIRIFERA. 33 



In Scotland it is found at Gare, Barrhead, Craigenglen, and Dallmellington, Dumfries- 

 shire, &c. In Ireland it is said to occur near Dublin, at Ballintrillic, and Millecent. 

 M. De Koninck mentions Vise, Chokier, and Ratingen among the foreign localities. 



Spirifera transiens, M'Cotf} Plate IV, fig. 2. 



Spirifera transiens, M'Coy. Synopsis of the Carboniferous Fossils of Ireland, p. 135, 

 pi. xix, fig. 14, 1844. 



" Spec. Char. Triangular or rhomboidal, including the beak, twice as wide as long, 

 gibbous ; mesial fold very large, prominent, rounded, undivided, producing a very deep 

 sinus in the front margin ; sides radiated, with about ten or twelve large, thick, rounded 

 ribs, equal or irregularly duplicate ; mesial fold with about six or seven ribs, equal in size 

 to those of the sides ; cardinal angles acute ; cardinal area low, triangular. 



"This species is nearlv allied to Sp. yrandceva of the Devonian rocks, but is 

 distinguished by its very large, undefined mesial fold, and more tumid sides. It differs 

 from Sp. bisulcata and Sp. attenuata in its very large, undefined mesial fold, and the 

 smaller number and greater size of its radiatory ribs, and most importantly by the cardinal 

 area, as in Cyrtia. Length one inch seven lines, width two inches six lines. Young 

 specimens are not so wide in proportion to the length (' Synopsis,' p. 135)." 



Mr. Kelly states that it is abundant at Clonalvy, Ireland. 



Spirifera grandicostata, M'Coy. Plate V, figs. 38, 39; Plate VII, figs. 7 — 16. 



Spirifera grandicostata, M'Corj. Annals and Mag. of Nat. Hist., 2d series, vol. x, 



1853 ; and British Palaeozoic Fossils in the Cambridge 

 Museum, p. 417, pi. iii d, fig. 29, 1855. 



Spec. Char. Transversely sub-rhomboidal or obtusely triangular ; hinge-line as long or 

 longer than the greatest width of the shell ; the lateral margins are regularly curved until 

 they reach the extremities of the hinge-line, or are abruptly attenuated towards the cardinal 

 angles, so as to produce acutely prolonged extremities ; valves moderately convex. The area, 

 with sub-parallel sides, is divided by a rather wide triangular fissure. Beak small, incurved, 

 and but slightly produced. The four or five ribs which ornament the mesial fold are, in 

 general, smaller and less defined than those which cover the lateral portions of the 

 shell ; the last, varying from ten to twenty-four on each valve, are very large, and either 



1 From not having been able to procure any example of this species, I am compelled to reproduce the 

 description taken from the ' Synopsis.' 



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