CONTENTS. 



Page 

 No. 1.— Contributions from the Zoological Laboratory. XV. Studies on 

 Lepidosteus. By E. L. Mark. (9 Plates.) February, 1890 1 



No. 2. — Contributions from the Zoological Laboratory. XVI. On the Egg 

 Membranes and Micropyle of some Osseous Fishes. By C. H. Eigenmann. 

 (3 Plates.) March, 1890 129 



No. 3. — Report on the Results of Dredging by the United States Coast 

 Survey Steamer " Blake." XXXII. Report on the Nudibranchs. By R. 

 Bergh. (3 Plates.) March, 1890 155 



No. 4. — A Third Supplement to the Fifth Volume of the Terrestrial Air- 

 Breathing Mollusks of the United States and adjacent Territories. By 

 W. G. Binney. (11 Plates.) May, 1890 183 



