48 Dr. T. Wright on neiv Species of Echinodermata. 



EXPLANATION OF PLATES I. II. AND III. 

 PLATE I. 



Fig. 1 . Cidaris Edwardsii : a, natural size, and restored to its globular 

 form ; 6, portion of an ambulacral area magnified, showing the 

 pi-clal pores and tubi-rck-s ; c, primary tubercle, with its circle of 

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

 natural size ; e , secondary spine, natural size and magnified ; 

 /, primary spines, natural size and magnified. 



"Fig. 2. Cidaris Bouchardii : a, b, natural size ; c, primary tubercle and 

 ambulacral area, magnified. 



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

 c, primary 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 Etheridgii : a, natural size ; b, upper surface and ovarial 

 plates, magnified two diameters ; c, under surface and mouth- 

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

 lacral area, magnified. 



PLATE II. 



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

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

 o?, 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 surface and ovarial disc, 

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

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

 and pedal pores, magnified. 



Fig. 4. Polycyphus 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 Woodwardli : 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 ; 

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

 bulacral area and pedal pores, natural size. 



PLATE III. 



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

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



c, under side, enlarged three diameters. 



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



rays, enlarged three diameters. 

 Fig. 3. Pentacrinus Goldfussii : natural size. 



