. A catalogue of the collection of Cambrian and Silurian fossils contained in the Geological Museum of the University of Cambridge. Paleontology; Paleontology. WENLOCK GROUP. 135 Case arid Column of Drawers. Beference to McCoy's Synopsis : and Figures of Genera. Names and References; Observations, & FC Orhiculoidea, p. 189. Gc7 FC FC PI. 1 H, figs. 4, 5, p. 255. See Athyris. BRACHIOPODA (Palliobranchiata). Are easily divisible into (1) homy and hinge- less shells (Lingula, Discina, Obolus), and (2) hinged calcareous shells, Orthis, Spirifer, &c. The passage from the young Lamellibra
. A catalogue of the collection of Cambrian and Silurian fossils contained in the Geological Museum of the University of Cambridge. Paleontology; Paleontology. WENLOCK GROUP. 135 Case arid Column of Drawers. Beference to McCoy's Synopsis : and Figures of Genera. Names and References; Observations, & FC Orhiculoidea, p. 189. Gc7 FC FC PI. 1 H, figs. 4, 5, p. 255. See Athyris. BRACHIOPODA (Palliobranchiata). Are easily divisible into (1) homy and hinge- less shells (Lingula, Discina, Obolus), and (2) hinged calcareous shells, Orthis, Spirifer, &c. The passage from the young Lamellibranch to the Brachiopod is easily seen by laying open a young Anodon (Rathke's Memoir). The heart is double, the intestine duplicate; the form of the opened valves, like that of Orthis biloba, and the median plate in so many Brachio- pods, is the sure indication of the real nature of these otherwise anomalous Bi- valves. Crania, Retzius. A well-known recent genus, which, with slight modifications, and very slight ones, has persisted from the Lowest Bala group to the present day. It inhabits deep water usually. Crania implicata, Sow. sp. (Patella? in the Silu- rian System. Orhiculoidea of D'Orbigny. Crania, Salter, Siluria, 2nd ed. pi. 20, fig. 4, Davidson, Sil. Brach. p. 80, pi. 8, figs. 13—17). The shell is a minute oval, imbricate outside, and with strong muscular scars. Crania Grayii, Davidson. (Sil. Brach. pi. 8, figs. 22—24.) Trematis (Discina) Siluriana, Davidson. Brach. pi. 8, figs. 19—20.) (Sil. Spondylobolus, McCoy. A genus unfortunately founded in mistake; a species of Meristella (probably M. obovata) being so pressed in shale, as to thrust the teeth through the opposite valve, and give rise to deceptive appearances. The formation also (this was not the Professor's error) is erroneous. The shell comes not from the black Lower Bala rocks of Builth, but from the equally black Wenlock shale. See No. 382. Numbers and Localities. a. 395, Dudley, V. C. a. 713, Dudley, F
Size: 1616px × 1545px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookaut, bookcentury1800, bookdecade1870, booksubjectpaleontology
