BLUE CHALK MARL. 97 



From Norlington Green. 



Fig. 8, the upper, and fig. 7, the under surface of the same specimen. 

 Fig. 14 is a younger example of this species. 



32. Tab. XXIX. figs. 9, 10. « A species of a genus of the family 

 CorystidcB^, allied to a new Indian genus in the cabinet of Dr. Leach." 



The shell is oblong, ovate, depressed ; the surface covered with minute 

 granulse, the margin bidentated near the front. No vestige of the legs? 

 antennae, or claws, remain. 



From Ringmer. 



Fig. 9, the under, and fig. 10, the upper surface of the same individual. 



33. Tab. XXIX. figs. 11, 12. " A species of the genus Etyus, of the 

 family Cancerida." Dr. Leach. 



Transversely obovate, obscurely trilobate; the surface covered with 

 irregular papiUae. 

 From Ringmer. 

 Fig. 11, the under, and fig. 12, the upper surface of the same example. 



34. Tab. XXIX. figs. IS, 15, 16. 



" These belong to a genus of the family Corystida, intimately related 

 to Corystes." Dr. Leach. 



This species is longitudinally obovate, convex, with a tuberculated 

 dorsal ridge, having a row of three tubercles on each side. The shell is 

 truncated posteriorly, and the margin laterally tridentated. The abdomen 

 is composed of six or seven arcuate segments, and there are three or four 

 legs on each side. 



Fig. IS. An imperfect specimen of the thorax. 



Figs. 15, 16. Different views of the same fossil. In the former, the 

 abdomen is seen folded beneath the thorax, and there are rudiments of 

 legs, on each side. The latter shews the upper surface with the tuber- 



* The Corystidw have four antennae ; the external pair approximate, setaceous, ciliated, 

 and very long. The eyes remote and pedunculated. The shell is aval, and longer than wide ; 

 the tail folded under the body when the animal is in a state of repose. They have ten legs ; the 

 anterior pair chelate, the others terminating in an acute elongated nail or claw. Vide Lamarck, 

 Atiimaua: satis Vertebres, tome V. 233. 



