from the Lias and Oolites. 383 



EXPLANATION OF PLATES XL XIL and XIIL 



Plate XL 



Fig. \. Cidaris Edwardsii : a, natural size, and restored to its globular 

 form ; b, portion of an ambulacral area magnified, showing the 

 pedal pores and tubercles ; c. primary tubercle, with its circle of 

 areal granules, magnified ; d, one of the jaws and its tooth, of the 

 natural size ; e, sccondar}" spine, natural size and magnified ; 

 f, primaiy spines, natural size and magnified. 



Fig. 2. Cidaris Bmichardii : a, h, natural size ; c, primary tubercle and 

 ambulacral area, magnified. 



Fig. 3. Hemicidaris minor : a, natural size ; b, magnified two diameters ; 



c, primar\' tubercle and ambulacral area, magnified. 



Fig. 4. Pedina Bakeri : a, natural size ; b, magnified one and a half dia- 

 meter ; c, primary tubercle and ambulacral area, magnified. 



Fig. 5. Pedina Etkeridgii : a, natural size ; b, ujiper surface and ovarial 

 plates, magnified two diameters ; c, under siu-face and mouth- 

 opening, magnified two diameters ; d, primary" tubercle and ambu- 

 lacral area, magnified. 



Plate XIL 



Fig. 1. Acrosalenia crinifera : a, natural size; b, upper surface, magnified 

 three diameters ; c, under surface, magnified three diameters ; 



d, primary tubercle and lateral granules, magnified. 



Fig. 2. Diadema Davidsoni : a, under surface and mouth-opening, natural 

 size ; b, upper surface and anal opening, natural size ; c. side 

 view, showing the tubercles of both areas ; d, base of one of the 

 ambulacral areas, showing the clustering together of the pedal 

 pores in this region ; e, primary tubercle, ambulacral area, and 

 pedal pores, magnified. 



Fig. 3. Diadema Moorei : a, natural size ; b, upper siu^'ace and ovarial disc, 

 magnified two diameters; c, imder surface and mouth-opening, 

 magnified two diameters ; d, primary tubercle, circle of granules, 

 and pedal pores, magnified. 



Fig. 4. Polycyphiis Deslongchampsii : a, natural size ; b, upper surface and 

 ovarial disc, magnified one and a half diameter ; c, outline of the 

 mouth-opening ; d, genital and ocular plates of the ovarial disc, 

 magnified ; e, primary tubercle, areal granules, pedal pores, and 

 ambulacral area enlarged. 



Fig. 5. Nucleolites Woodwardii : a, upper surface, of the natural size ; 

 b, side view, of the natural size ; c, ambulacral area and pedal 

 pores, magnified two and a half diameters ; d, tubercles and areas, 

 magnified ; e, mouth-opening and ambulacral area, magnified one 

 and a half diameter. 



Fig. 6. Nucleolites Michelini : a, upper surface, reduced one-third in size ; 

 b, lateral view, reduced one-third in size ; c, a portion of the am- 

 bulacral area and pedal pores, natural size. 



Plate XIIL 



Fig. 1. Opkioderma Gaveyi : a, disk, with portion of the rays, natural size ; 



b, part of the upper side of a ray, enlarged three diameters ; 



c, under side, enlarged three diameters. 



Fig. 2. Opkioderma Griesbachii : a, natural size ; b, disk and a part of the 



rays, enlarged three diameters. 

 Fig. 3. Pentacrinus Goldfussii : natural size. 



