160 PERMIAN FOSSILS. 
GERVAIHTAS eens @ Geinitz, Geea von Sachsen, p. 96, 1843. 
Myriivs acumrnatus, J. de C. Sow. De Verneuil, Bull. Soc. Géol. de France, 2™ série, 
vol. i, p. 32, 1844. 
sb, eicaly Fa Geol. Russ., vol. i, p. 224, 1845. 
— Hausmann, Goldfuss. Geinitz, Grundriss, p. 453, 1846. 
— Acuminatus, J. de C. Sow. Tennant, Strat. List, p. 88, 1847. 
— Havsmanni, Goldfuss. King, Catalogue, p. 9, 1848. 
— ACUMINATUS, J. de C. Sow. Howse, Trans. T. N. F. C., vol. i, p. 248, 1848. 
— HavsMANNI, Goldfuss. Geinitz, Versteinerungen, pp. 9, 10, pl. iv, figs. 12, &., 
1848. 
Diagnosis.—“ Ovate, acuminate, the lamin of the shell having the appearance of 
scales ; length more than an inch.” J. de C. Sowerby.’ 
Having examined the originals of this species in Mr. J. de C. Sowerby’s collection, 
I have ascertained that they are identical with the shells noticed in the above 
synonymy.” : 
As J. de C. Sowerby and Goldfuss have overlooked two or three important 
characters of this interesting species, it is necessary for me to add, that it is inequi- 
valved; has ecurved umbones, a horizontal septum within the umbonal cavity of each 
valve, and a wide longitudinally-grooved cartilage-furrow or fulcrum. Its muscular 
system has already been noticed; but it may be added, that the anterior visceral or 
pedal muscles, judging from the position of their impressions (vide Pl. XIV, fig. 7 0), 
have been situated much further back than is usual in M/ytilus : the relative position of 
the posterior adductor and posterior visceral muscular impressions is correctly repre- 
sented in the figure just noticed: the pallial line is even more strongly displayed on the 
fossil than itis in fig. 6. It is very often found nearly smooth, as in fig. 3; but under 
more favorable conditions, its squamose character, which results from the prominency 
of the incremental lamine, is finely displayed, as in the specimen represented in fig. 4. 
Mytilus squamosus is a widely-distributed species. “It occurs in considerable 
abundance near Ferry Bridge, but generally in the form of casts” (Sedgwick, Geol. 
Trans., 2d series, vol. iii, p. 120). The instructive specimen represented in Pl. XIV, 
figs. 6, 7, was collected by Mr. Binney at Hampole, in Yorkshire. It also occurs at 
Tunstall Hill, Dalton-le-Dale, Humbleton Quarry, and Silksworth. Dr. Geinitz records 
its occurrence in the upper Zechstein of Paschkowitz, Cosma, Lehndorf, Sommeritz, 
Schmélln, Roschitz, Kamsdorf, Elgersburg, Roda, Salzungen, Ahlstedt, Osterode, and 
Neuhof; also in the Dolomite of Miihlberg and Scharzfeld. 
1 Trans. Geol. Soc. Lond., 2d series, vol. i, p. 120. The following is Dr. Goldfuss’s diagnosis: ‘‘ Myt. 
testa ovata-acuta convexa lamellosa, umbonibus acutis, margine cardinali recto, latere infericre declivi, lineis 
concentricis subdistantibus.”’ (Petrefacta, p. 168.) 
2 Mytilus Hausmanni, Goldf., was incorrectly identified with Modiola acuminata in my ‘ Catalogue,’ p- 9. 
