162 PERMIAN FOSSILS. 



Mytilus sepiifer 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 Edmondiid^, King. 



This is a provisional group supposed to be related to Mytilidce, concluding from the 

 internal cartilage fulcra, edentulous hinge, and entire pallial line of its type. 



Genus Edmondia, De Koninck, 1843, 



Sanguinolama, Auct. 

 IsooARDiA (iinioni/ormis), 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, Isocardia unioniformis, Phillips. 



In the ' Annals and Magazine of Natural History' for November, 1845, 1 published 

 an account of a new genus, as a receptacle for certain fossils which had been generally 

 placed in Banguinolaria. 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 



^ " Testa tumida, sequivalvis, inaequilatera, transverso-subovalis, vel rotundata, transversim striata; lunula 

 biante ; dentibus cardinallbus nullis ; cardine lamella transversa, interna, ligamento interno idonea, munito." 

 Vide Description des Animaux Fossiles qui se trouvent dans le ter. carb. de Belgique. The following 

 is Dr. de Koninck's French description : " Coquille renflee, equivalve, inequilateral, transverse, subovale, ou 

 arrondie, couverte de stries nombreuses, transverses et concentriques ; lunule echancree ; charni^re depourvue 

 de dents, remplacees par une lamelle transverse, etroite, profondement situ^e et en partie recouverte par le 

 crochet et ayant probablement servi h. supporter un ligament interne, d'une forme a peu pres 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 striae consisting of minute tubercles," as displayed in the specimen represented in figure 5, Plate XX, 



