PLATE XVI II. 



Fig. 



] a. Amphiura Prattii, Forbes, p. 156. Under surfiice, natural size; this speci- 

 men belongs to the British Museum. 



b. „ ,, Portion of a ray, magnified four times. 



c. „ „ Ditto of the base, magnified four times. 



d. ,, ,, Lateral portion, magnified four times. 

 2. „ ,, Small specimen coiled up on a slab, 



natural size. British Museum. 

 3 «. Ophiurella Griesbachii, Wright, p. 154. Natural size, under surface; this 



specimen belongs to Dr. 

 Wright's collection. 



b. ,, „ The same, magnified three and a 



half diameters. 

 4- „ ,, Portion of a ray, showing spines, 



magnified six diameters. 

 5 «. OpnioDERMA TENUiBRACHTATA, For/5r.9. p. 14fi. Under surfacc, natural size, on 



a slab of Middle Lias sand- 

 stone; this specimen belongs 

 to Dr. Wright's collection. 

 h. „ „ Portion of a ray, magnified 



four times. 



c. „ „ Terminal portion, magnified 



four times. 



