152 



MEDITERRANEAN PROVINCE. 



species, but which had a Mediterranean settlement 

 as far back as the oldest tertiary deposits, was found 

 to be common at depths from fifteen to 200 

 fathoms. To these may be added the gregarious 

 Gidaris hystrix, and Spatangus purpureas, Echino- 

 cyamas pusillus, the smallest and prettiest of our 

 own urchins; a Brissus completes the Echinidce; 

 in all eight species, all Atlantic, and of which five 

 extend into our seas. 



Of the recognised Asteriadee, these same seas 

 contain our western "Spiny Crab-fish" ( Uraster 

 glacialis, Linn.) and the Palmipes membranaceus. 

 The northern seas, observes Ed. Forbes, greatly 

 exceed the Mediterranean in the number of species 

 and abundance of individuals of this order. Out 

 of the small number of the true star-fishes taken 

 by him one-half occurred only as single specimens. 

 So, also, with respect to the true urchins, — the edi- 

 ble species, so abundant in the central and Western 

 Mediterranean, is individually scarce in the iEgean, 

 as is also Spatangus purpureas. 



The Ophiuridce observed by Ed. Forbes in the 

 iEgean were eleven ; of these, four are Atlantic 

 species ; the rest, 0. texturata and albida, Amphi- 

 ura neglecta, and Ophiothrix rosula, are new, and 

 were procured from great depths ; one, the Ophi- 

 ura abyssicola, having been taken alive from 200 

 fathoms. 



Lastly, the Holoihuriadm are much more nume- 

 rous in the Western Mediterranean than the Eastern. 



