NUDIBRANCHIATA. 573 



genera are absent, such as Asteronotus, Kentrodoris, Casella, Melibe, Bornella, and Placo- 

 branchus^, and secondl}', the specimens are on an average considerably smaller than those 

 recorded from the Philippines, India, or East Africa. This latter feature is also noticeable 

 in the Tectibranchs (particularly the Pleurobranchoids) collected by Mr Gardiner, and I have 

 observed it in the specimens collected by myself at Samoa. It would seem as if the 

 marine fauna of small islands which have never been connected with a conti- 

 nent is less both in number and size than that of the mainland and its adjacent 

 islands. I am not however sure that a thorough examination of the Polynesian fauna 

 would bear out this conclusion, particularly as regards the number of genera and species. 



EXPLANATION OF PLATE XXXIL 



Doridomorpha gardineri nov. gen., nov. sp. 



I. Dorsal view of a preserved specimen. 2. Ventral view of the same. 3. Rhinophore pulled 

 out of its pocket after removal of mantle. 4. Mandible. 5. Edge of mandible more highly 

 magnified. 6. Teeth (a) central, (A) iirst lateral, (c) from centre of row, and (d) outermost. 



Notodoris gardineri nov. sp. 



7. Animal preserved in spirit about twice the natural size. 8. One lobe of tlie branchial valve. 



Hernvaea minor Bergh. 



9. Living animal, x 10. 10. One of the cerata. x 30. 



' These genera are recorded from the Philippines, Indian Archipelago, and South Seas, and I have found them 

 all abundantly on the East Coast of Africa. 



