CONTENTS. 



Page 

 No. 1. — Contributions from the Zoological Laboratory. XXVIII. Observa- 

 tions on Budding in Paludicella and some other Bryozoa. By C. B. * 

 Davenport. (12 Plates.) December, 1891 1 



No. 2. — Contributions from the Zoological Laboratory. XXIX. Tiie Gas- 

 trulation of Aurelia flavidula, Pe'r. & Les. By Frank Smith. (2 Plates.) 

 December, 1891 115 



No. 3. — Contributions from the Zoological Laboratory. XXX. Amitosis in 

 the Embryonal Envelopes of the Scorpion. By H. P. Johnson. (3 Plates.) 

 January, 1892 127 



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

 Breathing Mollusks of the United States and Adjacent Territories. By 

 W. G. BiNNEY. (4 Plates.) January, 1892 163 



