. Appendix to the Manual of Mollusca of Woodward, : containing such recent and fossil shells as are not mentioned in the second edition of that work . of the ventral valve. Distribution, 17 species. Silurian—Devonian. Europe, NorthAmerica. The forms marked by plications on the mesial fold and sinus,and sometimes with obscure or distinct plications on the lateralportions of the shell, constitute the genus Leiorhynchus, species. Devonian. United States. Charioxella, Billings, 1861. 1861, Synonym, Cryptonella, Hall, Type, Athyris scitula. Shell resembling Athyris, but more elon
. Appendix to the Manual of Mollusca of Woodward, : containing such recent and fossil shells as are not mentioned in the second edition of that work . of the ventral valve. Distribution, 17 species. Silurian—Devonian. Europe, NorthAmerica. The forms marked by plications on the mesial fold and sinus,and sometimes with obscure or distinct plications on the lateralportions of the shell, constitute the genus Leiorhynchus, species. Devonian. United States. Charioxella, Billings, 1861. 1861, Synonym, Cryptonella, Hall, Type, Athyris scitula. Shell resembling Athyris, but more elongate-ovate or ap-proaching to Terebratula in form. Internal spires as in Athyrisand Meristc., but the dorsal hinge-plate is either obsolete alongthe middle, or anchylosed to the bottom of the valve. Foramenterminal, bounded on the lower side by one or two deltidialpieces, or by a portion of the shell. The mesial septum in thedorsal valve is either absent or rudimentary. Distribution, 15 species. Devonian. America, Spain. Ntjcleospiea, Hall, 1859. Etymology, nucleus, and spira. Types, Spirifer pisum, Sowerby; Nucleospira ventricosa,Hall, Figs. 21, 22, r:g. 2i. Fig. venftneosa. Fig 23. Fig. 21, interior of the dorsal valve. Fig. 22, interior of the ventral valve. Fig. 23, interior of the dorsal valve, with a portion of the ventral valve , cardinal process ; c c, crural processes ; b b, dental pockets ; r, muscular impres-sions ; s, medio-longitudinal septum; 11, teeth; 2, a flattened space or false areabeneath the beak. (Hall.) 56 BRACHIOPODA. Shell punctate; spheroidal; beaked ; hinge line shorter thanthe width of the shell; cardinal extremities rounded. Internalspires as in Spirifera. Ventral valve with a flattened space orfalse area beneath the beak, on each side of which, at the base,is a strong tooth; a narrow medio-longitudinal septum extendsfrom the beak to the base. Dorsal valve furnished with a strongspatulate cardinal process, which, risi
Size: 3018px × 828px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdeca, booksubjectmollusks, booksubjectshells
