Plate 1\ 



I'ii/. I, Asiiilm nordiiln, attached tu tlie upper end of the tube of Pecti- 

 naria belyica Very slightly enlarged. 



/•'»/. i. Tlie same, from the other sid$. 



/•'/</. 3. Parascidia Flemingii, Alder, attached to a rootlel of tang] 



Fig. 4. Egg-case of Nassa incrassata, Strom. Enlarged. 



Fiii. 5. Tentacles of Cueumaria lactea. Enlarged. The oral orifice 



• i npies the centre. 



Figs. 6 & 7. Views of the oral region and tentacles of Synapta inharem 

 in different degrees of contraction. 



Fig. 8. Anchor and plate of the foregoing, x 280 diameters. 



Fig. 9. Section of the shell of Cancer pagurus, showing the internal 



processes of the hairs The preparation was mounted 1>\ the 

 late I ir. Fraser Thomson. 



Fig. lo. Young of common Mussel attached bj its byBsus to the carapace 

 of a Shore-( !rab. 



Fni. 11. Young Mussels in the eye-cavities of the same crustacean, 

 causing the peduncles to project, and partially blinding tie 

 Crab. 



Fig. 12. Defect of the carapace Lathe Shore-Crab, exposing the branchial 



chamber exterior to the first pair of toot-jaws. 



Fig. 13. Abdomen and part of the cephalothorax of a female Shore- 

 Crab, with :i parasitic Smi-tiliiia carcini and other abnormalities. 



Fig. 14. Sacculina parasitic on a male Portunus holsatus. 



Fig. 15. Another view of tin- same, with the tail reflected. 



