SPIRIFERA. 53 



At all ages Sjj. pin(juis presents a distinct, well-defined, and alnaost smooth mesial 

 fold, longitudinally divided by a shallow depression or furrow, but no such character is 

 exemplified in Martinis figure or description of his anomites rotundatus, which no doubt 

 belongs to another species. In his work on the ' Carboniferous Fossils of Belgium,' 

 Professor de Koninck has included Sp. ovalis and integricosta of Phillips among the syno- 

 nyms of Sp. rotundata, Sow. -^ but that distinguished author now admits the last two to be 

 distinct and specifically separate from Sowerby's species. All three must, however, be 

 considered as closely allied species, forming a well-defined group among the carboniferous 

 species of the genus to which they belong. 



Sp.pinguis is one of the most abundant fossils at Millecent, Little Island, Malahide, 

 and other Irish mountain limestone localities. In England it occurs at BoUand, Castleton, 

 and in the Isle of Man. I am not acquainted with any Scottish example. In Belgium it 

 was found at Vise and Tournay, by Professor de Koninck, and occurs also in several other 

 continental localities. ^ 



Spirifera ovalis, Phillips. Plate IX, figs. 20 — 26. 



SpiRlFERA EXARATA, Fleming (J) British Animals, p. 376, 1828. 



— ovALis, Phillips. Geol. of Yorkshire, vol. ii, p. 219, pi. x, fig. 5, 1836. 



— ROTUNDATA, Sow. De Koiiiuck, An. Foss. de la Belgique, p. 263, pi. xv, fig. 1, 



1843. 

 Braciiythyris ovalts, M'Coy. Synopsis of Carb. Foss. of Ireland, p. 145, 1844. 



— HEMisPHEiiiCA, M'Coy. Ibid, p. 145, pi. xix, fig. 10, 1844. 



SpiRiFEiiA OVALIS, Phil., = H/EMispHERiCA, M'Coy. British Palaeozoic Fossils, p. 419, 

 pi. 3 D, fig. 28, 1855. 



Spec. Char. Marginally elongated or transversely oval ; hinge line less than half the 

 width of the shell, with rounded cardinal angles. Dorsal valve moderately convex and 

 much less deep than the opposite one ; mesial fold broad, smooth, and well defined at all 

 ages ; depressed or obtusely rounded. From eighteen to twenty simple flattened or 

 rounded ribs ornament the surface of each valve. Ventral valve deep and gibbous ; beak 



ever as characters. As already stated, the measurements here given are those only of certain individual 

 specimens remarkable for their dimensions, or to show how variable different examples are in their compa- 

 tive proportions. 



' In his memoir ' Ueber die Fossiliea Schlesischen Kohlenkalkes,' lfcl54. Von Semenow gives as 

 synonyms of Sp. rotundata, Martin, Sp. rotundata. Sow., -S. ovalis, S. integricosta, Phillips, Sp. linguifera, 

 M'Coy, Sp. hemisphericum, M'Coy, Sp. ostiolata, V. Buch, and Sp. exarata, Fleming, but leaves out 

 (S/j. piw^Mi*, Sow., which he considers to be a distinct species. This synonym is defective in several 

 particulars. 



2 It is hardly necessary to observe that Baron Von Buch was decidedly in error wiiiie .stating, at 

 p. 184 of the French translation of liis memoir on Belthyrisis, that Sp. pinguis had been found in the 

 rocks of Dudley Castle and Wenlock Edge. 



