394 ROBERT TRACY JACKSON ON THE 



44. Lankestke, E. Ray. Mollusca. Encyclopaedia Britauuica, Niutb Edition, 1883. 



45. LE.i, Is.vAC. Observations on the Genus Unio, Vol. vi. Philadelphia, 1857. 



46. Lov£n, S. Bidras tiU Kaunedomen om utvecklingeu af Mollusca Acephala Lamellibranchiata. Kongl. Vetenskaps 



Akademiens Ilandlinger. Stockholm, 1848. Translated into German in Archiv f iir Naturgeschichte, Vol. xv, i, 1849. 

 A German reprint with plates was also published tjy Professor Lov6n, in 187'J. 



47. MiTZUKURi, K . Structure and Signihcance of some Aberrant Forms of Lamellibranchiate Gills. Quart. Journ. Mic. 



Sc. , 1881. Reprinted in Johns Hopkins Biol. Lab. Studies, Vol. u, 1883. 



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49. d'Orbigny, a. Palfiontologie Francaise, T. 3 et T. 4. 1843-47. 



50. Owen, Richard. Structure of the Shell iu the Water Clam (Spondylus varius). Proc. Zool. Soc, Vol. v, 1837. 



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1878. 



52. Patten, W. The Embryology of Patella. Arbeit. Zool. Inst. Wien, B. vi, 188fi. 



58. Eyes of Molluscs and Arthropods. Mittheilung d. Zool. Station zur Neapel, B. \^, 1885-G. 



64. Peck, R. Holman. The Structure of the Lamelliln-anchiate Gill. Quart. Journ. Mic. Sc, 1877. 



55. PiCTET, F. J. Molhisques Fossiles de Geneve. 



56. PuRDiE, Alex. The Anatomy of the Common Mussels. Colonial Museum and Geol. Survey Dept., Wellington, New 



Zealand, 1887. 



57. R.UJL, C. Ueber die Entwickelnngsgeschichte der Malermuschel. Jenaische Zeitschr., Vol. x, 1876. 



58. Reeve, L. A. Conchologica Icouica, London. 



59. Reichel, L. Ueber das Byssusorgan der Lamellibranchiaten. Zool. Anz., x, pp. 488-490. 



60. Ryder, John A. An Account of Experiments in Oyster Culture and Observations Relating thereto. Rep. Maryland 



Fish Comm., 1881. 



61. The Microscopic Sexual Characteristics of the American, Portuguese and Common Edible Oyster of Europe 



Compared. Bull. U. S. Fish Comm., Vol. u, 1882. 



62. ■ On the Mode of Fixation of tlie Fry of the Oyster. Bull. U. S. Fish Comm., Vol. n, 188^. 



63. On the Metamorphosis and Post-larval Stages of Development of the Oyster. Rep. U. S. Fish Comm., for 



1882. Washington, 1884. 



64. . A Sketch of the Life-history of the Oyster. Published in Ur. C. A White's Monograph (this list. No. 73). 



65. A Contribution to the Life-history of the Oyster, in "The Fisheries and Fishery Industry of the United 



States." Section 1, 1884, pp. 711-758. 



66. The Byssus of the Young of the Common Clam {Mya arenaria, L.). Am. Nat., Jan., 1889. 



67. Sharp, Benj.umin. Remarks on ttie Phylogeny of the Lamellibrancliiata. Proc. Acad. Nat. Sc. Phil., 1888. 



68. Schmidt, Ferdinand. Beitrag zur Keutniss der Postembryonaleu Eutwickelung der Najaden. Arcliiv fiir Naturge- 



schichte, LI, B. I, 1885. 



69. Sowerby, G. B. The Genera of Recent and Fossil Shells. London, 1821-26. 



70. SioLiczKA, Ferd. Cretaceous Pelecypoda of Southern India. Mem. Geol. Survey of India, 1871. 



71. Tryon, George W., Jr. Structural and Systematic Conchology. Philadelphia, 1882. 



72. Verrill, A. E. Invertebrate Animals of Vineyard Sound, etc. Rep. U. S. Fish. Comm. for 1871-72. 



73. White, C. A. A Review of the Fossil Ostreidse of North America. Rep. U. S. Geol. Survey, iv, 1884. 



74. On Mesozoic Fossils. Bull. U. S. Geol. Survey, 1884. 



75. Whitfield, Robeut P. Brachiopoda and Lamellibranchiata of the Raritan Clays and Greensand Marls of New Jer- 



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76. WiNSLOw, Francis. An Account of an Experiment in Artiflciiilly Fertilizing the Ova of the European Oyster. 



Rep. (— ) Maryland Fish Comm., 1881. 



77. Woodward, Henry. On the Structure of Camerated Shells. Pop. Sc. Rev., Vol. .xi, April, 1872. 



78. Woodward, S. P. Some Account of Barretia. The Geologist, Oct , 1883. 



79. Manual of the Mollusca. Fourth edition, by Ralpli Tate, London, 1880. 



80. ZiEGLEii, H. Ernst. Die Entwicklung von Cyclas cornea, Lam. Zeitschr. fiir wissensch. Zool., Vol. XLi, 1885. 



81. ZuTEL, Karl A. Traitfi de Palfiontologie. Translation by Dr. Charles Barrois, 1887. 



XVIII. EXPLANATION OF PLATES. 



The figures which illustrate this paper were drawn by Mr. J. H. Emerton or the author, with a few exceptions which 

 are noted in the descriptions. All figures of microscopic material were either drawn directly from specimens with the aid 

 of a Zeiss camera Incida, or were redrawn from camera drawings. The locality and date of collecting specimens are in- 

 dicated in the description of figures excepting cases where those facts are given in the text. The magnification of 

 figures and the principal references to the pages in the text where the figures are described or discussed are given as an 

 aid to readers. Specimens figured in the plates or text, unless otherwise mentioned , arc in the collection of the author. 

 I have to thank Mr. Emerton for the pains he has taken in drawing the figures which largely illustrate this paper. 



