50 THE VOYAGE OF H.M.S. CHALLENGER. 



In the Challenger the different species of Pourtalesise, of Echinothurise, of Hemi- 

 aster, of Schizaster, of Goniocickuis, of Cidaris, came up in numbers from certain 

 localities. 



My o-wTi experience has been identical, not only while collecting near the shores the 

 masses of Strongylocentrotus drobachiensis, of Arhacia, of EcJiinarachnius, of Mellita, of 

 Clypeaster, of Encope, of Rhynchopygus, of Moira, and in deep waters, oi Asthenosonui, 

 Scdenia, Aspidodiadema, Paleopneustes, and more particularly the species of Cidaris, 

 which, certainly if we had characterised our beds from such species as Cidaris tribuloides, 

 Dorocidaiis ■papillata, Dorocidaris hlakii, or Porocidaris, would give to a bed a very 

 different facies based upon very local distribution and occurrence in great numbers at 

 different localities. The same is true of the dredgings of Starfishes, Ophiurans, and 

 Holothurians. 



I have figured on Plate. XL. figs. 1-25, the differently shaped spines which occur on 

 specimens of G. tuharia. They have been selected to show the modifications of a simple 

 tapering spine (PI. XL. fig. 19), with slight nodes so as to form on the one side the spiny, 

 slightly cupuliform primary spines (PL XL. fig. 1), and on the other the short, cupuliform 

 spines (PL XL. fig. 1 8) characteristic of the abactinal part of the test, and the elongate, 

 slightly spinose, and but little cupuliform spines (PL XL. fig. 16) which give the extremes 

 of the forms of spines found in Goniocidaris tuharia. At the same time, the inter- 

 mediate forms showing the passage between these three extreme types give an excellent 

 idea of the great variation of the radioles in the genus Goniocidaris, and of the impossi- 

 bility of drawing reliable specific characters from the shape of the radioles alone, even when 

 taking carefully into account the ornamentation of the spines themselves, the nature of 

 which is frequently obliterated by the important changes in outline which characterise the 

 primary spines. This of course applies not only to this genus but in general also to 

 the species of the family Cidaridfe. 



Station 161. April 1, 1874. Off entrance to Port Philip; 38 fathoms; sand. 



Station 162. April 2, 1874. Off East Moncoeur Island, Bass Straits; 38 to 40 

 fathoms ; sand. 



Salenid^. 



Sub-family Salenidce, Agassiz, 1838, Moii. Ech. Sal6nies {emend.). 



Salenia. 



Scdenia, Gray, 1825, Ann. PhU. 



Tertiary Salenice are now known from France and from Australia, and also from 

 Sindh.^ 



' Cotteflu, Rev. and Mag. Zool., JIai. 1860. 



