Page:Quarterly Journal of the Geological Society of London, vol. 34.djvu/43

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R. ETHERIDGE, JUN., ON LOWER-CARBONIFEROUS INVERTEBRATA.
19

B. ETHEEIDGE, JTTN., ON LOWEE-CAEBONIEEEOUS ENTEETEBEATA . 19 Genus Mtjechtsonia, D'Archiac & De Verneuil. Murehisonia, D'Archiac & De Verneuil, 1841, Bull. Soc. Geol. de Prance, xii. p. 159. Muechtsonia STEIATUXA, De Koninck ?. PL II. fig. 29. Murchisonia striatula, De Kon. Descr. Anim. Foss. Terr. Carb. Belgique, 1844, p. 415, t. 40. fig. 7. Ohs. Our little shell approaches nearer to Prof. De Koninck's description than to any other I can find. Unless the Woodhall shells are young examples of M. striatula, the difference in size is very marked ; and, further, the ornamentation does not quite coincide with that of Prof. De Koninck's species. So far as I have been able to discriminate them, the ridges and grooves are less than twelve in number ; and the former are separated by more equal spaces than the grooves of M. striatula appear to be. The whorls vary in num- ber ; Mr. Henderson's specimens possess eight, whilst in the Survey Collection there is one from the same locality, collected by Mr. Bennie, with eleven whorls. Loxonema polygyra, M'Coy*, is nearer to the present shells in point of size, but is marked with much too few concentric ridges. Loc. and Horizon. In the shale with marine fossils at Woodhall. as before. Genus Belleeophon, De Montfort. Belleeophon decussatus, Fleming, var. undatus, R, Eth., Jun. PL II. fig. 30. I described this variety in the ' Geological Magazine ' for April (1876)f . It differs from the typical form in having a series of broad obtuse fluctuations or waves in the direction of the transverse striae. The latter are clearly visible in young specimens ; but in older and larger individuals they become obscured or obsolete, or nearly so. Loc. and Horizon. Woodhall, as before. Class PTEROPODA. Genus Conulaeia, Miller. Conularia (Miller), Sowerby, Mineral Conchology, iii. p. 107. Conulaeia sp. ind. Ohs. One fragment only has come under my observation in Mr. Henderson's collection ; but in the Geological Survey Cabinet there are two others which, although only portions also, afford more in- formation than the other. The specimens represent a part of one of the faces of the pyramid with its median ridge. The transverse

  • Synop. Carb. Foss. Ireland, 1844, p. 30, t. iii. fig. 1.

t Decade 2, vol. iii. p. 155, t. vi. figs. 9, 10. c2