552 p. H. CARPENTEK ON CEETACEOUS COMATUL^. 



(fig. 6, 5, c). The dorsal pole is smooth and slightly flattened. Most 

 of the sockets, are large and pear-shaped with the small end down- 

 wards, the largest being nearly 2| by 1| mm. An articular ridge 

 crosses the broadest part and widens out in the centre round the 

 transverse opening of the axial canal. The margins of the sockets 

 are coarsely striated. 



The ventral surface has a shallow and irregular central cavity, 

 with traces of small radial extensions (fig. 6, a). The basal grooves 

 are well marked, with high parallel walls that stand up above the 

 level of the intervening radial areas, which are more or less irregu- 

 larly hollowed (fig. 6, c). 



Diameter 4 mm. ; height about 3| mm. 



Locality. The Chalk of Wylye, in Wiltshire. Both this and the 

 following species belong to the cabinet of the Eev. P. B. Brodie, 

 M.A., E.G.S., who has kindly placed them in my hands for descrip- 

 tion. 



RemarJcs. The few but large cirrhus-sockets of this species and 

 its deeply cut basal grooves distinguish it very markedly from the 

 other fossil Comatulce. The sockets of A. paradoooa are sometimes 

 as long, but they have entirely different articular surfaces (fig. 4). 



5. Antedon inctjeva, n. sp. (PI. XXIII. fig. 1.) 



The centrodorsal is hemispherical, with a pentagonal outline, and 

 is almost completely covered by about forty-five polygonal cirrhus- 

 sockets, arranged in five or six more or less irregularly alternating 

 rows. At the dorsal pole is a trace of a stellate impression (fig. 1, 6). 

 The margins of the sockets are striated, and the transversely oval 

 opening of the central canal seems to have had a rim with raised 

 ends as in A. striata (fig. 5, d). 



The sides of the radial pentagon are rather curved inwards, so that 

 it does not quite cover the centrodorsal (fig. 1, «), while its angles 

 project slightly beyond the edge. The outer dorsal surfaces of the 

 radials are just visible, especially at the angles, where they are 

 turned upwards and separated by small rounded basals that project 

 slightly outwards, so as to be visible when the calyx is viewed from 

 either above or below (fig. 1, a,h). 



The articular faces of the radials are high relatively to their 

 width and much curved from above downwards, as well as from side 

 to side (fig. 1, c, d). Only one of them is at all free from the 

 matrix. It shows a considerable enlargement of the ventral rim of 

 the axial canal, from which a median ridge runs upwards to meet a 

 wide notch between the muscle-plates, while two others run up- 

 wards and outwards to separate the muscular fossae from those for 

 the interarticular ligaments. The form of the central funnel is 

 stellate, but somewhat irregular ; for at three of the angles there is 

 no notch between the muscle-plates of two adjacent radials, while 

 at two others these notches are visible, owing to the tips of the plates 

 being somewhat everted. 



