DESCRIPTION OF THE PLATES. 123 



PLATE IX. Fig. 9. Small longitudinal portion of shell from the large 

 claw of Cancer Pagurus, showing the thickness of 

 the annulus or ring in it at the point of separation. 

 Fig. 12. Longitudinal section of one of the legs of Can- 

 cer PaguruSj shewing the natural position and 

 relations of the reproductive organ. 

 a a Femur. 



b b Reproductive organ. 

 c Natural appearance of line of separation. 

 d Coxa. 



Fig. 13. Enlarged foramen as it is seen on raw surface 

 after the separation. This has been hardened 

 in boiling water, which gives it a much more 

 defined appearance, and also enlarges it more 

 than it naturally should be. 



Fig. 14. Is a small portion of the femoral artery, about 

 half an inch in extent beyond the line of separa- 

 tion, which is covered as represented bv the 

 peculiar vessels. 

 a Distal extremity of blood-vessel. 



ON THE ANATOMY AND DEVELOPEMENT OF THE 

 CYSTIC ENTOZOA. 



PLATE VII. Fig. 1. Magnified view of one of the young of Acephalo- 

 cystis armatus still attached to the germinal mem- 

 brane of a secondary parent. It is taken from 

 the group shewn in Fig. 2, and is still in an 

 early stage of developement, the circlet of teeth 

 still being minute and not fully developed. The 

 absorbing series of cells may be seen internally. 

 Fig. 2. Small portion of the germinal membrane of a 

 secondary parent of Acephalocystis armatus highly 

 magnified. 



Fig. 3. Small portion of germinal membrane of Acepha- 

 locystis armatus in a state of degeneration ; no- 



