191 



Description of Plate II. 



Fig. 1. Cynthia Flemingii. 



... 2. Part of inferior antennae, with scale. 



... 3. Natural size of Cynthia Flemingii. 



... 4. Themisto longispinosa. 



... 6, The third and fourth subabdominal fins ; a, peduncle of the third ; 

 6, external branch ; c, internal branch ; d, peduncb of the fourth 

 subabdominal fin ; c, internal branch ;/, the long external branch. 



... 6. The superior antennal scale of T. longispinosa. 



... 7. Nat size of T. longispinosa. 



... 8. Middle caudal plate. 



... 9. T. brevispinosa. 



... 10. The third and fourth subabdominal fins of T. brevispinosa ; the let- 

 ters refer to the same parts as those in the same drawing of thy 

 T. longispinosa. 



... 11. Natural size of T. brevispinosa. 



... 12. The middle caudal plate. 



Description of Plate III. 



Fig. 1. Caprella spinosa. 



... 2. Natural size. 



... 3. Ovarian plate, and one of the branchial fins attached, it shews -the 

 upper or concaved surface with the hooJsed spioes. 



... 4. Caprella laevis, magnified. 



... 5. Natural size. 



... G. Caprella tuberculata, magnified. 



... 7. Natural size. 



... 8. Caprella linearis, magnified. 



... 9. Natural size. 



... 10. Ma^ified lateral view of the second and third thoracic segment? of 

 CapreUa spinosa, shewing how the segments become changed dur- 

 ing spawning, with the ovarian plates and branchial finlets in the 

 natural position. 



... 11. Enlarged view of Ovaries A. and Oviducts JB. ; a^ anteiior ^tr^- 

 niity ; 6, posterior. 



... 12. Zoo of Pcujurus BemharduSf lateral view. 



... 13. Back view. 



... 15. Ocular tubercles. 



... 14. Caudal segment. 



... 16. Lateral view of the Zoe of the Cardnus maaioi, sometime befo)^ 

 it has escaped from the ovum. The tunics of the egg have been 

 stripped ofi". 



... 17. Last abdominal segment, and caudal fork of the same, shewing the 

 curious brush-shaped appendages ; these drop ofif when the animal 

 has escaped from the ovum, and are replaced by spines. 



