3G8 CARBONIPEROUS LAMELLIBRANCHIATA. 



regarded as synonymous with Phillips's species. De Koninck, neglecting 

 S. angustatus, considered S. discors as the type of the genus, and noted its 

 occurrence in the Carboniferous Limestone of Vise. 



This species is quoted by Young and Armstrong as occurring in the Upper 

 Limestone series of Bowertrapping and the Lower Limestone series of Craigen- 

 glen in the west of Scotland ; but I am not able to confirm their diagnosis, 

 having met with no specimen of this species from those localities. 



I have, however, seen two specimens of the species in the collection of Mr. R. 

 Craig, of Beith, from the Kerrsland Glen beds (upper part of the Lower Limestone 

 series of the west of Scotland). One of these is figured, PI. XL, fig. 6. 



Fig. 5, PL XL, is the only specimen I have met with showing the 

 external characters of the species so "well preserved. Lamellibranchs preserved 

 in limestone rarely have the exterior of the valve in its original condition. 



I do not think that any other species of the genus can be confused with 

 8. angustatiis. The only two which have any even superficial resemblance to it 

 are S. clavatus, which is more convex and has a narrowed posterior end, and 

 S. argutus, which is more convex, less transverse, and has a very distinct 

 obhque ridge and a deeper concave dorsal slope. 



I wonld draw attention to the great resemblance between Allorisnia costata, 

 Meek and ^Yorthen (oj;. cit.), and ;S'. angustatiis. Judging simply from the figure and 

 description of the American shell, I can see no specific difference between them. 



Sanguinolites argutus, Phillips, sp., 1836. Plate XL, figs. 15, 16. 



CucuLLJEA ARGUTA, PhilUps, 183G. Geol. Yorks., pt. 2, p. 210, pi. v, fig. 20. 

 Akca arouta, de Kon., 1843. Foss. Carb. Belg., p. 116, pi. iii, figs. 1 & 12. 

 CucuLL.'EA AEGUTA, Mori'is, 1843. Cat. Erit. Foss., Ibt edit., p. 84. 



— — M'Coy, 1844. Synops. Carb. Foss. Ireland, p. 72. 



Arca ARG0TA, de Verneuil, 1845. Geol. Russie, etc., vol. ii, p. 313, pi. xix,fig. 12. 

 CucuLL^A ARGUTA, JSrouu, 1848. Noinenclat. paljeontol., p. 356. 

 Arca arouta, d' Orhirpiy, 1850. Prodrome Palcoutol., vol. i, p. 134. 

 CucuLL^A ARGUTA, Morris, 1854. Cat. Brit. Foss., 2ud edit., p. 197. 



— — Griffith, 1860. Jouru. Geol. Soc. Dubliu, vol. ix, p. 92. 

 Arca arguta, d'Eichwald, 18G0. Lethsea Eossica, vol. i, p. 988. 



Non — — Armstrong and Young, 1871. Trans. Geol. Soc. Glasgow, vol. iii, 



Supplement, p. 49. 

 — — — Armstrong, Young, and Sohertson, 1876. W. Scott. Foss., p. 53. 



— — Bigiibi/, 1877. Thesaurus Devouico-Carbouiferus, p. 298. 



Macrodon arouta, von Mdller, 1880. Congres Internat. Geol. Paris, p. 117. 

 ? Parallelodox argutus, de Koninch, 1885. Ann. Mus. Eoy. Hist. Nat. Belgique, 



vol. xi, p. 154, ])1. XV, fig. 40. 



