Echinoidea — Sea-urchins 8f Asteroidea — Starfishes. 95 



Echinolampas subrostrata, in British seas at this period, is a Sea- 

 significant fact in distribution, for it shows that the land barrier ^^^ 



Ct AT T l'*B.Y 



which formerly separated this region from the Southern Ocean had vill. 

 been breached. East Side. 



The foreign sea-urchins are shown in Wall-cases 15-17. The ^*^^**^**®* 

 Palaeozoic collection is exhibited in the last. The American genus 

 Melonites is represented by two fine specimens on the slope, and 

 two groups in frames at the back of the case. The Jurassic 

 fauna is on the floor of Wall-case 16: it includes the types of 

 three French species of Hemipedina, and some large specimens 

 of Rhahdocidaris. The Cretaceous species occupy the remainder 

 of Wall-case 16, and part of the lowest shelf of 15c. A large 

 specimen of Semipneustes striato-radiatus, from Belgium, mounted 

 on a block on the uppermost shelf in 15b, should not be 

 overlooked, as it is the largest sea-urchin in the collection. Some 

 species of Clypeaster are only a little smaller, and a fine series 

 from the Cainozoic rocks of the Mediterranean Basin and the 

 West Indies is shown in blocks in this wall-case. The Cainozoic 

 Echinoids are the most important of the foreign collections, 

 including a large series of the types of those from Malta and 

 Australia. A large broken specimen from Barbados {Cystechinus 

 crassus) is of interest, as it is the only fossil belonging to any 

 of the higher groups that has as yet been found in the deep-sea, 

 oceanic marls of Barbados. 



III.— AsTEROTDEA. Asteroldea 



— Star- 

 This class includes the common Starfish ; but not the Brittle- fishes. 



Wall-cases 

 16 & 17, 

 Table- 

 cases 75, 

 76a, & 76. 



Fig. 152.— Section of a ray of a Starfish, Uraster ruhem, Linn., sp., showing 

 the arrangement of the calcareous ossicula. 



Stars, which are Ophiuroidea, nor the Rosy-Feather Star, which 

 is a crinoid. The starfishes differ from the sea-urchins by not 



