162 PERMIAN FOSSILS. 
Mytilus septifer occurs “at Byers’s Quarry, Whitburn, Roker, Suter Point, and 
Marsden, in a formation probably the equivalent of the German Rauchwacke”’ 
(Catalogue, p. 10); also in the same formation south of Black Hall Rocks on the 
coast of Durham (Sedgwick). Specimens of what is considered “a larger species, 
length half an inch” (but perhaps only an enlarged form of the present one), “ occurs in 
the upper thin-bedded limestone at Cold Hill, a few miles east of Aberford” (Sedgwick). 
It probably occurs in some of the Zechsteins of Germany. Count Keyserling figures a 
fossil under the name of Mytilus Hausmanni (but which, I suspect, belongs to the 
present species), found in the Permian rocks of Petschora-land. 
Family EpMonvDiIIDzm, King. 
This is a provisional group supposed to be related to A/ytilide, concluding from the 
internal cartilage fulcra, edentulous hinge, and entire pallial line of its type. 
Genus Hdmondia, De Koninck, 18438. 
SANGUINOLARIA, duct. 
IsocarDIA (untoniformis), Phillips. 
SANGUINOLITES (angustata, Phillips), M‘Coy, 1844. 
Diagnosis. —‘Shell tumid, equivalved, unequilateral, transverso-suboval, or rounded, 
striated transversely, the lunula gaping; no hinge teeth; hinge with a small transverse 
thin plate, internal, greatly strengthened by an internal ligament.” (De Koninck.) 
Type, Lsocardia unioniformis, Phillips. 
In the ‘ Annals and Magazine of Natural History’ for November, 1845, I published 
an account of a new genus, as a receptacle for certain fossils which had been generally 
placed in Sanguinolaria. The characters of the genus were principally derived from 
two species apparently closely related to each other, viz. Sanguinolaria sulcata, Phillips, 
and Hiatella sulcata,’ Fleming. Although closely resembling each other, these species 
1 «Testa tumida, eequivalvis, ineequilatera, transverso-subovalis, vel rotundata, transversim striata; lunula 
hiante ; dentibus cardinalibus nullis ; cardine lamella transversa, interna, ligamento interno idonea, munito.”’ 
Vide Description des Animaux Fossiles qui se trouvent dans le ter. carb. de Belgique. The followmg 
is Dr. de Koninck’s French description: ‘Coquille renflée, equivalve, inequilateral, transverse, subovale, ou 
arrondie, couverte de stries nombreuses, transverses et concentriques ; lunule échancree ; charniére depourvue 
de dents, remplacées par une lamelle transverse, etroite, profondement située et en partie recouverte par le 
crochet et ayant probablement servi a supporter un ligament interne, d’une forme a peu prés analogue.” 
(Loc. cit.) 
2 In my paper referred to in the text, this shell is identified with the Pholodomya elongata of Dr. Morton 
(vide Ann. and Mag. of Nat. Hist., vol. xiv, pp. 316-17); but since it was written, I have ascertained that 
the shell named Hiatella sulcata by Dr. Fleming, in his ‘ British Animals,’ p. 463, is the same species, and 
consequently quite distinct from the Sanguinolaria sulcata of Professor Phillips, who was disposed to regard 
both as specifically identical. I had long suspected the shell in question to be the same as Dr. Fleming’s 
Hiatella sulcata, from its agreeing with this species in being “closely and obsoletely striated longitudinally, 
the strize consisting of minute tubercles,” as displayed in the specimen represented in figure 5, Plate XX, 
