lUU SVKN LOVEN, ON TUE ECHINOIDEA DESCRIBED BY LINN^-US. 



arrano-c thcmselves, largely developed, in angular arcs bor- 

 (lerino- on the middle suture, thus fillmo- the narrow open 

 tircola, Tab. 7, fig 1. Ventrally, where this areola coutracts 

 thev graduallv disappear. 



In colour the Linnean specimens are slightly different, 

 probablv from difference of age and from bleaching. The 

 specimen a is diill white with a very faiut tinge of rose; the 

 calyx grey; the interradial disks present a slight shade of 

 brownish grey with a lighter line along the sutiire; the tuber- 

 cles white with the mamelons green; the zones brick-coloured ; 

 the under side whitish all över. The specimen 6 is of a light 

 orey with a slight tinge of rose, a rather vivid red tint tra- 

 versing from beneath the pellucid granules; the very slight 

 shades on the disks somewhat bhiish, with the middle sutural 

 line reddish; the mamelons greenish, afew of them red; the zones 

 light crimson. The specimens c and d are dull white, the inter- 

 radia grev, bordering npou livid, the sutural line påle reddish ; 

 the mamelons greenish, some reddish; the zones reddish brown. 



LlNN^us said that his Echinus Lixula like the three 



preceeding species was not to be found in any author, and 



referred to the E. saxatilis the fig. A on the fourteenth plate 



of RuMPHius, which likely enough may have been meant for 



it. In 17")2 he was still imiorant of Klein's book. Fourteen 



vears låter, when for a loug time he had not again seen the 



original specimens of the Queen's Mviseum and had no oppor- 



tunity of comparing them, he got a sight of its French trans- 



lation of 1754, and in the S. N. ed. 12, p. 1103 erroneously 



referred to the E. Diadema one of the ligures given there, 



Pl. V^I, fig. 6", which is an imitation of Klein's FL XI, fig. A. 



Had he been able, when first describing the E. Lixula, to com- 



parc the figures given in the original edition, fig. A^^ and C, 



1 think he could not have failed to recognise in both the 



species he had before him. It is the same marked smallness 



of the tubercles, their conspicuoiis rarity on the upper parts, 



and the same ambulacral areola, even the adveutitious tubercles 



are not missing. One of the type specimens in Klein's col- 



') I shall not venture to give any opinion on the fig. B, at p. 21 

 referred together with the fig. A to the var. « of the Cidaris assulata 

 pustulosa. Its greater size, its convexity and crowded tubercles forbid 

 its association with the fig. A. while the small stoma removes it from any 

 known species of Arbacia. It is not unlikely that the marginal letter,? 

 p. 21 have been misplaced, and that the fig. B alone belongs, as a bad 

 tigure, to «, »pastulis densis>, and fig. A with C to (i, >pustalis rarioribua». 



