96 



Guide to the Invertelrata. 



Asteroidea 

 — Star- 

 fishes. 



GALLEEY 



VIII. 

 East Side. 



Wall-cases 

 15 & 17, 

 Table, 

 cases 

 76 & 76. 



having a closed skeleton of regular, closely-fitting plates. The 

 main skeleton consists of a series of plates on the under surface 

 of the body ; above, it is usually leathery and supported by rods 

 arranged in an open mesh work. (Fig. 152.) 



The oldest starfishes in the British collection are Palcemterina 

 Kinaliani and Palceaster Caractaci, both represented by casts in 

 rocks from the Caradoc, or uppermost division of the Ordovician 

 system. Specimens from the Wenlock Limestone are in better 

 preservation, notably a fine example of Lepidaster Grayi, at the 

 end of Table case 75. 



The Jurassic collection contains some fine starfishes, notably 

 Asterias Gaveyi, Solaster Moretonis, and a massive Pentagonaster 

 Sharpi, from the Northampton Ironstone. Some large specimens 



Fig. 153. 

 Palaasferina stellata, Billings (under surface). Ordovician (Trenton 



Limestone) : Ottawa. 

 Pula-asterina primccva, Forbes (upper surface) . Upper Silurian : Kendal. 



of species included in the comprehensive genus Astropeeten a^e 

 shown in Wall-case 17. 



The Cretaceous collection contains specimens which are in even 

 better preservation than those of the Jurassic ; and it includes 

 most of the types of the species described by Sladen in his 

 monograph of the Cretaceous Asteroidea. The specimens especially 

 worthy of note are those of Calliderma Smithi. 



The Cainozoic fauna consists only of some species from the , 

 London Clay of Sheppey, many of w^hich are in an imperfect 

 condition of preservation. 



The foreign starfishes are shown in Wall-case 17a. It contains 

 some interesting forms from the French Jurassic, and a valuable 



