86 BRITISH PALEOZOIC ASTEROZOA. 



A sinofle row of small adradialia runs down each side of the radialia as far as the 

 fifth supero-marginal. 



Nearly all the supero-marginalia are finger-shaped, with the long axis of the 

 finger pointing distalwards. They are large plates, especially conspicuous in the 

 proximal region of the arm. The first four supero-marginalia occupy about two- 

 thirds o£ the arm-length. All the apical plates possess granules which may have 

 carried spine-pits. 



Text-fig. 46. —Plan of the ajjical surface of the disc and one ai'ni of Mesopalceaster complicatus 

 (based on D. 7-i and D. 133). x 12. 



Arm in Side View. — Casts from D. 172 show a side view of the proximal 

 portion of the arm. The supero- and infero-marginalia are seen to alternate. One 

 or two scattered intermarginalia are present. 



Oral Surface (Plate III, fig. 8; Text-fig. 45).— Both I). 70c and D. 172 

 give good casts of the oral surface. The odontophors are somewhat small, 

 and have migrated proximalwards so far that the neighbouring infero-marginalia 

 meet for about half their length along an interradius. The first six infero- 

 marginalia are large and conspicuous. Beyond these there are a number of small 

 infero-marginalia. Only three are drawn in the figure, but probably more could 

 be seen if a clear view of the side of the distal portion of the arm could be 

 obtained. 



