146 SVEN LOVEN, ON TlIE ECHINOIDEA DESCRIBED BY LINN^EUS. 



National Museum as from Sandwich Islands, Townsend, (3554), 

 diam. 77 mm., lieight 52 mm. or 0,675, kindiy sent me for 

 inspection by Professor RiCH. Kathbun, had oiglit tubercles in 

 eacli interradial series. It seemed to be distinct by the difFe- 

 rent disposition of tlie seeondary verrucse in the ambulacral 

 areola, by its broader median interradial zone, and the very 

 uarrow marginal oue. as bv the lower form of the test. The 

 accompanying spines were as described, -^ but the range of 

 variation of these organs, and its causes, are vet to be more 

 closely studied. 



It would be fully legitimate to name the species described 

 by LiNNJEUS in 1752: Cidaris Cidaris L., v^^ere it not that its dia- 

 gnosis, when about to be published for the first time in 1758, 

 was altered, the most essential Avord: »globoso» of the primitive 

 readino- beins exchanoed for »hemisphgerico», a term in no wise 

 expressive of the form of the type specimen. Whereas the dia- 

 gnosis in its first form fully served to distinguish the Echinus 

 Cidaris from every other Echinus in the Queen's collection, in 

 consequence of this alteratiou it not only excluded that spe- 

 cies for which it was originally intended, but became insuffi- 

 cient to distinguish between different species within the whole 

 genus in its present acceptation. The description would un- 

 doubtedly have cleared the question and removed any ditticulty, 

 but there is none in the M. L. U. To account for its absence 

 it may perhaps be allowable to siippose that Linn^us, who 

 in 1757 no lono-er had a vivid recollection of the orioinal 

 specimen and no hope of seeing it again, had before him at 

 Upsala some other species of the genus and that the descrip- 

 tion drawn up at Drottningholm, when found not to answer, 

 was sacrificed, while the diagnosis was adjusted to suit the 

 other. Be tliis as it may, the species name : Cidaris L., left 

 to its fäte bv the author himself, is to be laid aside as 

 without validity, though of some historical interest. 



As mentioned alreadv there is in the Drottninoholm col- 

 lection a second specimen of a Cidaris not to be raistaken as 

 having been the E. Cidaris L. Thcy differ widely from onc 

 another and Linn^us surely never would have thought of uni~ 

 ting them. This second species is: 



