CLASS I PELECYPODA 423 



elastic Wjament, and closed hy the contradion of musdes attadied to the inner faces of 

 the valves ; feeding hy ciliary adion and destitute of a radula or jaw ; breathing hy 

 lateral gills ; im'perfedly sensible to light and rarely provided with peripheral Visual 

 Organs ; possessing olfadory organs (osphradia)^ auditory and equilibrating organs 

 (otocysts), tadile papillae, and a nervous system composed of ganglia united hy nerves^ 

 but without a pedovisceral commissure ; provided with an extensile, tadile or loco- 

 motor organ (foot) ; a circulatory system containing haemolymph, and operated hy a 

 Single or paired cardial ventricle and two aurides ; a more or less convoluted intestinal 

 ca7ial, with its oral and anal extremities at opposite ends of the hody ; a stomach ; 

 paired nephridia, conneded with the pericardium, and discharging independently of 

 the redum ; reproducing without copulation, hy ova and spermatozoa ; monoecious or 

 dioecious ; development external to the ovary ; the post-larval stage proteded hy a 

 prodissoconch, and sometimes exhihiting special nepionic stages. 



External Charaoters. The Shell. — The embryonic Pelecypod is provided 



Palaeoiit, Soc, 1896-1905. — Ulrich, E. 0., Lower Silurian Lauiellibranchiata of Minnesota. Rept. 

 Geol. Surv. Minn., 1897, vol. iii. 



B. On Mesozoic Forms : Benecke, E. W., Die Versteinerungen der Eisenerzformation von 

 Deutsch - Lothringen und Luxemburg. Abh. Geol. Spezialkarte Elsass - Lothring., 1905, n.s., 

 vol. V. — Bittner, A., Revision der Lamellibranchiaten von St. Cassian, Abh. Geol. Reichsanst. 

 Wien, 1895, vol. xviii. — Böhm, O., Die Bivalven der Stramberger Schichten. Paläont. Mittheil. 

 Mus. Bayer. Staates, 1883, vol. ii. — Borrissyak, A., Die Pelecypoden der Jura- Ablagerungen im 

 europaischen Russland. Mem. du cours geol., nouv. ser., 1904-9. — Broili, F., Die Fauna der 

 Pachycardientuffe der Seiser Alp. Palaeontogr., 1903-7, vols. 1., liv. — Coquand, W., Monographie 

 du genre Ostrea des terrains cretaces, 1869. — Healey, 31., The Fauna of the Napening beds 

 (Rhaetic) of Upper Burma. Palaeont. Indica, 1908, n.s., vol. ii., no. 4. — Holzapfel, E., Die 

 Mollusken der Aachener Kreide. Palaeontogr., 1887, vol. xxxiv. — Kitchin, F. L., The Jurassic 

 Fauna of Cutch. Lamellibranchiata. Palaeont. Indica, 1903, ser. ix., vol. iii., pt. 2. — Lavhe, O., 

 Die Fauna von St. Cassian. Denkschr. Akad. Wiss. Wien, 1866, vol. xxv. — Pavloto, A., Enchaine- 

 ments des Aucelles et Aucellines du Cretace Russe. Nouv. Mem. Soc. Imper. Nat. Moscou, 1009, 

 vol. xvii. — Pompeckj, J. F., Über Aucellen und Aucellen - ähnliche Formen. Neues Jahrb. f. 

 Min., 1901, Supplem. vol. xiv. — Qiiaas, A., Beitrag zur Kenntniss der Fauna der obersten 

 Kreidebildung in der Lybischen Wüste. Palaeontogr., 1902, vol. xxx. pt. 2 — Stoliczka, F., 

 Cretaceous Fauna of Southern India! The Pelecypoda. Mem. Geol. Surv. East India, 1871, vol. 

 iii. — Waagen, L., Die Lamellibranchiaten der Pachycardientuffe der Seiser Alp. Abh. Geol. 

 Reichsaust. Wien, 1907, vol. xviii. pt. 2. — Wood, H., Monograph of the Cretaceous Lamelli- 

 branchiata of England. Palaeont. Soc, 1899, vol. \m.~Zittel, K. A. von, Die Bivalven der 

 Gosaugebilde. Denkschr. Akad. Wiss. Wien, 1865-66, vol. xxv. 



C. On Tertiary Forms : Androussov, JV., Fossile und lebende Dreissensidae Eurasiens. Trav. 

 Soc. Imp. Sei. Nat. St-Petersb., sect. geol., 1897, 1903, vols. xx., xxix. — Arnold, R., The 

 Tertiary and Quaternary Pectens of California. U.S. Geol. Surv. Profess. Papers, no. 47, 1906. — 

 Bellardi, L., and Sacco, F., 1 Molluschi terziari del Piemonte e della Liguria. Torino, 1872-1901. — 

 Cossvumn, M. , Catalogue illustre des coquilles fossiles de l'Eocene des environs de Paris. Fase. 

 Ann. Soc. Malacol. de Belgique, 1888-89, vols, xxiii., xxiv.—Idem, and Pissaro, ^ G., Iconographie 

 complete des coquilles fossiles de l'^^ocene des environs de Paris. Fase. 1, Pelecypodes, 1904. — 

 Dali, W. H., Contributions to the Tertiary Fauna of Florida, i.-vi. Trans. Wagner Inst. Sei., 

 1890-1903, vol. in.— Deperet, G., and Roman, F., Monographie des Pectinides neogenesde l'Europe 

 et des regions voisiues. Mem. Soc. Geol. France, 1902, vol. x. — Fontannes, F., Les Mollusques 

 pliocenes de la Vallee de Rhone et du Roussillon. Lyons, 1879-83.— G^regrorto, A., Monographie 

 de la faune eoci'nique de l'Alabama. Palermo, 1890. — Ä^ams, G. D., Bull. Amer. Palaeont.,- 

 1895-97, vols. i.-iv. — Hoernes, M., Die fossilen Mollusken des Tertiärbeckens von Wien. Abhandl. 

 Geol. Reichsanst. Wien, 1870, vol. iv.—Koenen, A. von. Das norddeutsche Unter-Oligocän und 

 seine Mollusken-Fauna. Abhandl. Geol. Spezialkarte Preussen, 1889-93, vol. x.—Oppen}wim, 

 P., Zur Kenntnis alttertiärer Faunen in Ägypten. Palaeontogr., 1903-6, vol. xxx. pt. 3. — 

 Ortmann, A. E., Families and Genera of the Najades. Ann. Carnegie Mus., 1912, vol. viii. no. 

 x. — Sandherger, F., Die ■ Conchylien des Mainzer Beckens, 1860-63.— /rfm. Die Land- und 

 Siisswasser - Conchylien der Vorwelt. Wiesbaden, \9>n. — Schaff er, F. X., Die Bivalven der 

 Miocänbildungen von Eggenburg. Abh. Geol. Reichsanst. Wien, 1910, vol. xxW.— Simpson, C. J., 

 Synopsis of the Naiades or Pearly Fresh-water Musseis. Proc. U.S. Nat. Mus., 1900, vol. xxii., no. 

 1205. — Ugolini, R., Monografia dei Pettinidi neogenici della Sardegna. Palaeont. Ital. 1906-7, 

 vols. xii., xnl— Wood, S., Monograph of the Eocene Bivalves of England. Palaeontogr. Soc, 

 1861-71. 



