THE LAMELLIBRANCHS OF THE SILURIAN ROCKS OF GIRVAN. 483 



1854. Murchison, Siluria, 1st ed., on pp. 191, 225, and 226, woodcuts of lamellibranchs from Lower 



Silurian and two from Upper Silurian beds are given, with names. In the 3rd ed., 1859, and 

 4th ed., 1867, the numbers of the pages and woodcuts are altered, and a new cut is introduced at 

 p. 50, and p. 48 of the 4th ed. of Fossils from the West Side of the Stiper Stones. All forms 

 had been previously described and figured. At the end of the 3rd and 4th eds. are plates 

 copied from those in the Silurian System, but rearranged and reduced in size to suit the style 

 of the book. 



1855. M'Coy, British Palaeozoic Fossils, figured the following : — Pterinea pleuroptera, Conrad, sp. ; 



P. subfalcata, Conrad, sp. ; P. tenera, M'Coy; P. asperula, M'Coy; P. hians, M'Coy; P. retro- 

 flexa, Wahl, sp. ; do. var. B. naviformis, Conrad; P. megaloba, M'Coy; Avicula Danhyi, 

 M'Coy ; Modiolopsis inflata, M'Coy ; M. modiolaris, Conrad, sp. ; M. Nilsoni, Hisinger, sp. ; 

 M. post-lineata, M'Coy ; Orthonotus nasutus, Conrad ; Sanguinolites decipiens, M'Coy ; S. anguliferus, 

 M'Coy ; Area subxqualis, A. Edmondiiformis, Nucula levata, Hall ; Nuculites poststriutus, Emmons ; 

 Clidophorus ovalis, M'Coy; C. plauulatus, Conrad; Anodontopsis quadratics, M'Coy; A. bulla, 

 M'Coy; A. angustifrons, M'Coy; Ambonychia acuticostata, M'Coy; Lyrodesma plana, Conrad; 

 Tellinomya lingulicomes, M'Coy ; Leptodomus truncatus, M'Coy ; Grammysia rolundata, Sow., 

 sp. ; G. cingulata, var. triangulata, Salter ; G. extrasulcata, Salter ; Dolabra obtusa, M'Coy ; 

 Tellinites affi?iis, M'Coy ; Anodontopsis securiformis, Dolabra elliptica, Leptodomus globulosus. 

 1858. Billings, amongst others, proposed the genera Maltheria and Cyrtodonta for groups of Lower Silurian 

 shells with a well-marked hinge plate (Canadian Naturalist and Geologist, vol. iii.). 



1860. Eichwald, Lethsea Eossica, describes and figures a number of species ; but as I am not able to state 



correctly which are Silurian species, I do not attempt to give a list. 



1861. Barrandb, Acephales, vol. vi. This volume contains lists and enumerates many new genera erected 



for Silurian lamellibranchs, and has several plates of figures. 

 1861. Salter (Mem. Geol. Sure. Scotland, No. 32, "The Geology of the Neighbourhood of Edinburgh") 



describes and figures Lunulacardium elegans, Orthonota amygdalina, var. gentilis, 0. bulla, 



Anodontopsis ? lucina, Ctenodonta obesa, C. thracioides, from the Silurian rocks of the 



Pentland Hills. 

 1S66. Salter, Mem. Geol. Surv. Gt. Britain, "The Geology of North Wales," in which are described 



Palxarca Billing dana, P. obscura, P. modiolaris, P. (Maltheria) quadrata, P. bulla, P. socialis, 



P. amygdalus, Ctenodonta varicosa, Redonia anglica, Ribiera ? complanata, Modiolopsis pyrus. 

 1873. Hicks, Q.J.G.S., vol. xxix. p. 39, " On the Tremadoc Kocks in the Neighbourhood of St David's, 



South Wales, and their Fossil Contents," in which he figures twelve species belonging to five genera, 



of which Glyptarca and Davidia are new. 



1875. Meek, Geological Survey of Ohio, vol. ii., pt. ii., " Palaeontology," in which are described Tellinomya 



levata, T. pectuncidoides, Lyrodesma cincinnatiensis, Pterinea demissa, Ambonychia radiata, 

 Sedgivickia? divaricata, Orthodesma contractu, 0. curvata, 0. recta, Cuneamya miamiensis, 

 C. scapta, Grammysia neglecta, Modiolopsis truncata, M. cincinnaticensis, M. pholadiformis, 

 M. modiolaris, M. concentrica, from Lower Silurian, and Cypricardites ferrugineum and 

 Amphicoelia costata from Upper Silurian rocks. 



1876. Rxemer, Ferd., Lethsea Palseozoica, in which figures of the following fossils are given from Lower 



Silurian rocks: — Ctenodonta nasuta, Salter; Megalomus ? Deshayesianus, Murchison, de Vern., and 



Keys.; Ambonychia radiata, Hall; A. incrassata, Eichwald, sp. ; Modiolopsis modiolaris. 

 1881. Barrande, Systeme Silnrien de la Boheme, vol. vi. This work contains a large number of new genera, 



which are described and figured. He recognises fifty-eight genera of lamellibranchs, of which 



twenty-nine are new. 

 1886. Walcott, Bull. U.S. Geol. Surv., No. 30, p. 123, describes Fordilla troyensis, from the Upper 



Taconic of North America. 



1889. Miller, North American Geology and Paleontology. This work gives a list of all North American 



genera and species of fossils, amongst which are a few new genera for Silurian lamellibranchs, and 

 references to the earliest publication of each. 



1890. Walcott, 10th Ann. Rept. U.S. Geol. Surv., "The Fauna of the Cambrian or Olenellus Zone." Two 



new genera, Fordilla and Modioloides, are described. 



