94 REPORT — 1876. 



In the Anomiira they are only adapted for swimming in the long-tailed 

 forms ; but in Erachyura they are only utilized for the suspension of ova in 

 the female, and never used for swimming except in very young animals, and 

 reduced to two pairs only in the male, where they are interlocked in each 

 other and adapted as organs aiding intromission, 



I cannot close this portion of the report without expressing great admi- 

 ration of the valuable memoir of Milne-Edwards, so frequently quoted in 

 these pages. With the exception of Professor Huxley's Hunterian Lectures, 

 St. George Mivart's Memoir on the Lobster in the ' Popular Science Eeview,' 

 and a Memoir on the same subject by J. S. Kingsley, recently published 

 in the 'American JN^aturalist' (Aug. 1876), little has been written on this 

 subject of late years. 



It is remarkable that so large and important a class of animals should 

 have been left so long without being anatomically studied, and it is to be 

 hoped that the important' part that they must take in the great history of 

 progressive evolution will gradually induce naturalists to give them the 

 attention that their importance deserves. 



EXPLANATION OF THE PLATES. 



Plate IL 



Fig. 1. Sternum from Palinurus. 



2. Sternum from Ncphrops. 



3. Sternum from Lithodes, 



4. Sternum from Cancer. 



.5. Sternum from Cancer, lat. est. aspect, t Dorsal notcli. 



G. Sternum from Cancer, longitudinal section. * Ventral sinus. 



7. Spinal processes attached to legs in Megalopa. 



8. Eyes from Palinurus. 



9. Eyes from Cancer. 



10. Eyes from Alphteus, adult. 



11. Eyes from Alphceus, young. 



12. Eyes from Amphipoda. 



1.3. Antenna, first, from Anchistia. 



li. Otolith from same. 



1.5. Antenna, first, Mysis, male. 



16. Antenna, second, Hcyllarus. 



17. Antenna, second, Cancer. 



18. Anteima, second, Pontia. 



Plate III. 



19. Mandible from Ncbalia. 



20. Mandible from Pontia. 



21. Mandible from Palamon. 



22. Labium, postei-ior, from PaUmirus. 



23. Deutognathe from Cancer, adult. 



24. Deutognathe from Cancer, young.' 



25. Tritoguathe from Cancer, adult. 



26. Tritoguathe from Cancer, young. 



27. Tetartognathe, or maxilliped of authors. Cancer. 



28. Tetartoguatlie, or ma?iilliped, of Amphipod. 



29. Gnathopoda from Cancer, young. 



30. Gnathopoda from Cancer, adult. 



31. Gnathopoda from Macrura. 



32. Gnathopoda from Squilla. 



33. Gnathopoda from Amphipoda, 



