CHAPTER IT. 

 PART II. 



FOSSIL STELLERIDJE STARFISHES CRINOIDEA ENCRINITES PULLEY- 

 STONES MARSUP1TES APIOCRINITES LILY ENCRINITE PENTACRINITES 

 PETREMITES. 



FOSSIL STELLERID.E. WaU-Cose G. Under this name are 

 comprised two groups of radiated animals; namely, the 

 Aster idee, or Starfishes, and the Crinoidece, or Lily-shaped 

 zoophytes, of which there are specimens of many species and 

 genera in the case to which I would now direct attention. 



The zoophytes, popularly called Starfishes, from their 

 stellular forms, are so generally diffused through the seas 

 surrounding our Island, that the common five-rayed Asterias 

 must be familiar to every one, and will serve as an illustra- 

 tion of the general appearance and structure of the beings 

 whose petrified remains are the subject of examination. This 

 species belongs to the division in which the rays are elongated 

 and far exceed in length tne diameter of the disc ; in another 

 group (the Cushion-stars), the body is angular, and the lobes 

 or rays are short, and not longer than the diameter ; while in 

 a third subdivision (Comatula and Ophiura), the arms are 

 distinct from the body, and elongated and articulated, as in 

 the Crinoidece. 



The external surface of the common Starfish is soft, and 

 attached to a tough coriaceous integument, investing a skele- 

 ton composed of numerous calcareous ossicula, arranged in 

 regular series along the margins of the rays. Each ray has 

 a longitudinal furrow or groove, perforated at the sides by 

 alternating rows of pores through which tubular tentacula are 

 protruded. The mouth is situated in the centre of the under 



