CHIM^RC 



In the newly depositec 

 smaller, together with the 

 capsules shown in plate u, 

 chians (Riickert). Its cons 

 thus, shortly before breakir 

 sistency that it will flattei 

 Its ellipsoidal outline is a; 



Fig. 30. F.arly ovarian egg of Chimaera col 

 around it the extent of the space indie 

 arterial blood supply ; /, peritoneum ; i 



Figs. 3 1 and 32. Sections of the marginal 

 indicating changes in the tunic and t 

 by, botryoidal yolk masses developec 

 membrane surrounding egg; g-x, gona 

 /. inmost layer ; /;; , middle layer ; o, 



present an almost spherica 

 capsule be opened (plate i . 

 cream. 



No. 



No. 



No. 55. A Revision of the Pelycosauria of North America. By E. C. 



Case. Quarto. In press. 

 No. 56. The Energy Changes involved in the Dilution of Zinc 



and Cadmium Amalgams. By T. W. Richards and G. S. Forbes. 



Octavo. In press. 



No. 57. The Roman Comagmatic Region. By H. S. Washington. 



Octavo, 199 pages. In press. 



. 58. Variation and Differentiation in Ceratophyllum. By Ray- 

 mond Pearl. Octavo. In press. 

 , 59. The Pawnee : Mythology. By G. A. Dorsey. Octavo. lu 



press. 

 No. 60. Hydrates in Aqueous Solutions. By Harry C. Jones. 



Octavo. In press. 



No. 61. The Electromotive Force of Iron under Varying Condi- 

 tions and the Effect of Occluded Hydrogen. By T. W. Richards 



and G. E. Behr. Octavo. In press. 

 No. 62. Condensation of Vapor as induced by Nuclei and by Ions. 



By Carl Barus. Octavo. In press. 

 No. 63. The Electrical Conductivity of Aqueous Solutions. By 



Arthur A. Noyes and others. Octavo. In press. 

 No. 64. Variation and Correlation in the Crayfish, with special 



reference to the Influence of Differentiation and Homology of 



Parts. By Raymond Pearl and A. B. Clawson. Octavo. In press. 

 No. 65. (See No. 35.) Investigation of Infra-red Spectra. III. Infra- 

 red Transmission Spectra. IV. Infra-red Reflection Spectra. 



By W. W. Coblentz. Octavo. In press. 

 No. 66. High Steam Pressures in Locomotive Service. By W. F. M. 



Goss. Octavo. In press. 

 No. 67. The Fauna of Mayfield Cave. By A. M. Banta. Octavo. 



In press. 

 No. 68. (See No. 18.) Researches on North American Acridiidse. 



Part II. By A. P. Morse. Octavo. In press. 

 No. 69. Further Researches concerning the Atomic Weights of 



Potassium, Silver, Chlorine, Bromine, Nitrogen, and Sulphur. 



By T. W. Richards in collaboration with Arthur Staehler, G. S. 



Forbes, Edward Mueller and Grinnell Jones. Octavo. In press. 

 No. 70. Selection and Cross-breeding in relation to Inheritance of 



Coat-pigments and Coat-patterns in Rats and Guinea Pigs. By 



Hansford MacCurdy and W. E. Castle. Octavo In press. 

 No. 71. Atlas of Absorption Spectra. By H. S. Uhler and R. W. 



Wood. Quarto. In press. 

 No. 72. Investigation of Inequalities in the Motion of the Moon 



Produced by the Action of the Planets. By Simon Newcomb. 



Quarto. In press. 

 No. 73. Explorations in Turkestan: ArcheologicalandPhysiograph- 



ical Results of Expedition of 1904, under direction of Raphael 



Pumpelly. Reports by Raphael Pumpelly, Herbert Schmidt, J. 



E. Durst and R. W. Pumpelly, with contributions by F. A. 



Gooch, Langdon Warner, Ellsworth Huntington, and Homer 



Kidder. Quarto. In press. 

 No. 74. The Vulgate Version of the Arthurian Romances A 



faithful reproduction of Mss. in the British Museum, by 



H. Oskar Souimer. Quarto. In press. 



November 17, 1906. 



THE OVARIAN MEMBRANES. 



Comparison with corresponding stages in shark (Pristiurus) shows that the 

 wrappings of the ovarian eggs of Chimxra are the more complex. In early stages of 

 the latter the ovarian tunic is thicker and its nuclear elements more abundant and 

 more evidently specialized. Thus in fig. 30, which shows in section an egg of about 

 5 mm. , one notes the thickness of the tunic ; this (greatly enlarged) is shown in 



