76 BRITISH PALEOZOIC ASTEROZOA. 



however, two of the plates touch along their length. This, I think, is due to post- 

 mortem displacement. A madreporite may be present in one of the small spaces 

 figured immediately distal to a primary interradial and between two supero- 

 marginalia. It is difficult, however, to be quite sure of the presence of this plate. 

 By far the most prominent plates of the disc are the primary radialia, which are 

 remarkably large and swollen, reminding one very much of the corresponding 

 plates of the Cretaceous Starfish StaiiranJerasfer hulbiferus, Forbes. 



The proximal radialia immediately behind the primary radial are breastplate- 

 shaped and alternate with the supero-marginalia. Distally, as usual, they become 

 rounded and opposite to the supero-marginalia. 



38 39 



Text-fig. 38 (on left).— Plan of the apical .surface of the disc and one arm of Coccasler bulhiferus (based 



on the specimen in the Royal Scottish Museum), x 6. 



Text-fig. 39 (on right).— Plan of the oral surface of an arm and moutli region of Coccasfer hulhifrvus (based 



on the specimen in the Ludlow Museum), x 6. 



The majority of the supero-marginalia are finger-shaped and swollen. The first 

 pair are much the largest of the series. 



The arm is terminated by a distinct ocular. 



Oral Surface (Plate III, fig. 2; Text-fig. 39). — The mould of the oral surface 

 also gives very clear impressions. The ossicles appear to have been somewhat 

 disturbed, but it is not difficult to make a restoration. The odontophor is a pro- 

 minent plate of characteristic form. Its proximal extremity is distinctly pointed, 

 and the sides which border the ambulacral grooves are slightly concave. Its distal 

 side is notched in the middle. From the notch a groove passes on to the face of 

 the ossicle, which is distinctly swollen. The infero-marginalia are of the usual 

 shape and are not conspicuously differentiated. Their ornament is described 

 below. There are approximately three ambulacralia to each two infero-marginalia 

 throughout the arm, except possibly at the extreme tip. Small detached spines 

 are seen overlying the adambulacralia. 



The ossicles bordering the moutli have fallen inwards, and the appearance is 

 somewhat confused as the cast shows the inner sides of the apical ossicles. The 



