ECHINOIDEA. II. 



^73 



ning og Havfiske. igo6. 1:1.82) certainly deserves to be nained as a di.stinct variety; I propose to nanie 

 it var. fuscus n. var. As pointed out (loc. cit.) it differs from the t}'pical form in tlie lower form of 

 the test and in the uniformly red coloured spines, the spines of the typical form being generally violet 

 at the point, wliite in the lower part (occasionally the .spines are green). According to Appellof the 

 spines of tliis variety may vary considerably in colonr, from beautifully cinnabar-red to green; in all 

 the specimens seen by me they are uniformly red. The spines are somewhat longer than is generally 

 the case in the typical form. The pedicellariæ do not show any differences from those of the typical 

 form. The measuremeuts given liere show the considerable difference in height between the variety 

 and the typical form, though there is certainly some variation in this regard also. 



This variety seems to be found exclusively in the North Sea. The specimens in our Museum 

 are from the following localities : 55° 30' N. 1° E. 75 M., 56° 40' N. 2° 16' E. jt, M. and 57° 55' N. 1° 20' E. 

 105 M. — It is evidently the same form which is mentioned by Th. Scott (Notes on some Scottish 

 Echinodermata. Ann. Scott. Nat Hist. 1892. p. 49), who also gives a figure of the naked test (PL II. 

 Fig. i). He does not mention the colour of the spines. — In a specimen of this variety, which I exa- 

 mined in the Berlin Museum, the spines on the buccal piates were partly transformed into sjjhæridiæ, 

 all transitional stages being found between common spines and true sphæridiæ. In mj- paper «Eclii- 

 noderms from East Greenland* (Medd. om Gronlaud. XXIX. 1903. p. 77 — 78) I have taken the occasion 

 to mention that and given some figures thereof. 



&' 



In the beautiful work of J. L/ambert: «Description des Échinides fossiles de la Province de 

 Barcelone. II— III. Échinides des Terrains miocéne et pliocéne ,' which I received after the printing 

 of the main part of the present work, so that it could not be taken into consideration there, some 

 important critical remarks are given, on which a few words may be said here. 



The genus Parccliiiius, established by me in Part I of this work for ^-sEchinusi) miliaris, micro- 

 tuherctdatus and aiigulosus, is not accepted by Lambert, who maintains that the name Psa)in?icc/iiiiits 

 must be retained for this group, whereas the name Anapcsus Holmes has to be used for the group 

 to which I have limited the genus Psammechmus , viz. P. varicgafits (or Blaijivillci Desm., as Lam- 

 bert shows to be its right name), scniitubcrcidattis etc. Lambert's reasons for maintaining this are, 

 that the older authors have taken miliaris as the type of the genus Psaiiiiiiccliiiius. and that varicgatus 

 (Blainvillei) and the species of that group are not quite in accordance with the original diagnosis. 

 To this may be remarked that none of the previous authors have understood the real characters of 

 the genera of the Echinidæ and allied groups.- I was the first to give exact diagnoses of these 



1 Mém. Soc. Géol. de France. XIV. 1906. 



2 Even Lambert himself has not the right couception of these genera. Ce qui distingue PsatiiiticchinuSf, he says 

 (p. 67. note), «ce n'est pas seulement la présence de plaquettes imbriquées sur la inenibrane buccale, c'est la forme de son 

 péristome plus large, subdecagonal, c'est surtout l'homogénéité de ses majeures ambulacraires, toutes tuberculiféres, tandis 

 que chez Echinus adulte les majeures alternent, successivement tuberculiféres et granuliféres, comme celles de Toxopneustes"- 

 This is not correct; several species of Echinus, e. g. elegans, Alexandyi a. o. have a primary tubercle on every ambulacral 

 plate — but scarcely anybody, who knows these species in nature, not from literature alone, would think of excludiug them 



