3G2 CARBONIFEROUS LAMELLIBRANCHIATA. 



Sanguinoi.ites (pars), de Koninck, 1885. Ann. Mus. Eoy. Hist. Nat. Eelgiiiue, 



vol. xi, p. 58. 

 Sl'Henotus, Hall, 1S85. Nat. Hist. N. York Palieontol., vol. v, pt. 1 ; Lamellibr., 



vol. ii, p. xxxiii. 

 Sanouinolites (pars), Yonng, 1888. Trans. Geol. Soc. Glasgow, vol. viii, p. 293. 



— — Etheridge, 1888. Brit. Foss., pt. 1, Palseozoic, p. 2S9. 



Leptodomus (pars), Etheridge, 1888. Ibid., p. 284. 



Sanouiisolitks (pars), Miller, 1889. N. Amer. Geol. Palseontol., p. 509. 

 Sphenotus, Miller, 1889. Ibid., p. 513. 

 Noil Sanguinolites, Etheridge in Ward, 1890. Trans. N. StafF. Min. Mecb. Eng., 



p. 127. 

 — — Meek and Worthen, 1890. Pal. Illinois, vol. viii, p. 129. 



— Tornquist, 1896. Fossilfiilir. Untercarbon. Sudvogesen, Abb. 



geol. Karte Elsass-Lotbr., pt. 2, vol. v, 

 p. 119. 



Generic Characters. — Shell transverse, oval ; the ends rounded, the posterior 

 deeper in the dorso-ventral diameter than the anterior ; very inequilateral, 

 compressed, strongly carinate, with a much-compressed and hollowed dorsal 

 slope, often crossed by one or more radiating lines or ridges. Lunule and 

 escutcheon large, the latter bounded externally by an erect, curved ridge. 



Interior. — The anterior adductor muscle-scar is large, deep, and bounded 

 behind by a curved, ridge ; the posterior shallow, remote from the hinder 

 margin, and placed close beneath the hinge. Pallial line entire. The hinge is 

 probably edentulous in all species, certainly in some, with a rolled and thickened 

 and elongated margin posteriorly. 



Exterior. — The surface is ornamented with parallel concentric ribs or lines, 

 Avhich, as a rule, pass into stride on the posterior slope. Surface tuberculated, 



Ohservafions. — The genus Sanguinolites was erected by M'Coy in 1844, and 

 included shells previously described by Phillips under Sanguinolaria, together 

 with others newly described by M'Coy. It lias been correctly pointed out by de 

 Koninck and others that several of the shells referred by M*Coy to Sanguinolites 

 were so different in character that they could not be correctly included in one 

 genus. Hence very great confusion has arisen as to the limitation of the genus, 

 which has been made worse by the invention of new genera, which in a large 

 measure have included shells which can be referred to Sanguinolites, if the 

 type of that genus be taken as S. angustatus, the first species described under the 

 genus. 1 consider the correct solution of the difficulty is to take this species 

 as the type of the genus, and to include in it only those shells which have 

 undoubted affinity to it. 



Fortunately, too, S. angustatus is a very typical shell of the genus. M'Coy, 

 while recognising the species, re-described it under the synonym S. discors. 



