PLATE XXIX. 



Pycinastee ceassus, n. sp. (Page 96.) 



From the Upper Chalk. 

 Pig. 



1. Actinal aspect of a small specimen; natural size. (Coll. Brit. Mus., E. 2570.) 



2. Abactinal aspect of surface of arm of type specimen; natural she. (Coll. Brit. Mus., 35498.) 

 a. Supero-niarginal plate; magnified 3 diameters. 



3. Supero-marginal plate ; natural size. (Coll. Brit. Mus., E. 2631.) 

 a. Side view of same ossicle ; natural size. 



•4. Isolated ventrodateral plate ; magnified 2 diameters. (Coll. Brit. Mus., E. 2632.) 

 a. Isolated plate from abactinal surface of disc; magnified 2 diameters. 



5. Madreporite; natural size. (Coll. Brit. Mus., E. 2628.) 



Pyoinasteu senonensis, Valette, sp. (Page 95.) 

 From the Upper Chalk. 



6. Outer view of abactinal ossicle of disc; natural size. (Dr. Blackmore's Collection.) 

 a. Side view of same ossicle ; natural size. 



Nymphastee eugosus, n. sp. (Page 9-A.) 

 From the Lower Chalk. 



7. Actinal aspect ; natural size. (Coll. Brit. Mus., 57516.) 

 a. Infero-marginal plate ; magnified 6 diameters. 



Staueandeeastee aegus, ii. sp. (Page 99.) 

 From the Upper Chalk. 



8. Actinal aspect ; natural size. (Dr. Blackmore's Collection.) 

 a. One of the ventrodateral plates ; magnified 2 diameters. 



9. Inner view of three ossicles isolated from a specimen in the British Museum ; figured by Forbes ; 



magnified 2 diameters. E. 2566. [See also Plate XXV, fig. 6.] 

 a. Outer view of same ossicles ; magnified 2 diameters. 



Aetheastek ceistatus, ii. sp. (Page 93.) 

 From the Upper Chalk. 



10. Side view of segment of arm, restored ; natural size. (Dr. Blackmore's Collection.) 



a. Outer view of a radiale ; magnified 4 diameters. 



b. Side view of same ossicle ; magnified 4 diameters. 



Aetheastee Dixoni, Forbes, sp. (Page 91.) 

 From the Upper Chalk. 



11. Ossicle from abactinal surface of disc; natural size. (Coll. Brit. Mus., E. 5024.) 

 a. The same ossicle ; magnified 3 diameters. 



Metopastee coenutus, Sladen, sp. (Page 117.) 

 From the Upper Chalk. 



12. Ultimate supero-marginal plate of adult specimen ; magnified 2 diameters. (Dr. Rowe's 



Collection.) 



Ophiotitanos magnus, ii. sp. (Page 106.) 

 From the Lower Chalk. 

 13. Abactinal aspect; magnified 2 diameters. (Coll. Sedgwick Mus., Cambridge.) 



