POLYCERELLA ZOOBOTRYON.i 

 By W. M. Smallwood. 



Presented by E. L. Mark, October 12, 1911. Received December 30, 1911, 



Contents. 



Page 



I. External Characters 609 



11. The Systems of Organs 611 



1. The Integument 612 



2. Anatomy of Digestive System 613 



3. Histology of " " 616 



4. The Liver 616 



5. The Kidney 617 



6. The Heart and Blood Gland 618 



7. Anatomy and Histology of the Reproductive System . 618 



8. The Genital Ducts 622 



9. The Nervous System 624 



10. Histological Structure of the Pedal GangUon .... 626 



11. Special Sense Organs 628 



I. External Characters. 



In a previous paper (Smallwood, : 10), the general external features 

 of this new species (Figure 1) were described; a part of that descrip- 

 tion follows, as I desire to present at 

 this time a complete account of the 

 morphological characters of the spe- 

 cies — the histology as well as the 

 anatomy. 



" Polycerella zoobotryon is a small 

 nudibranch, from 5 to 6 mm. in length Figure 1. Polycerella zoobo- 

 and 1 1/2 mm. wide. The body is tryon, dorsal view. Magnified 8 

 thickest just anterior to the branchial diameters, 

 plumes. The shape is much as in 



Polycera — elongated, narrow, and about as high as broad. Body com- 

 pressed, smooth, sloping rather abruptly from the branchial plumes 



* Contributions from the Bermuda Biological Station for Research No. 24, 

 and from the Zoological Laboratory of Syracuse University. 



VOL. XLVII. — 39 



