OCR Text |
Show 424 PROF. F. J. BELL ON THE ECHINOMETRIDsE. [Mar. 15, ECHINOMETRA MACROSTOMA. The single spineless test which, as it seems, should be referred to this species, gives the following measurements : - Greatest length, in millim. 45 Morphol. axis, in millim. 435 Percentage value of Height. 50-5 Actinostome. 43-9 Abactinal area. 206 Anal area. 11-2 It will be of great interest to examine the buccal apparatus of this rare species. The specimen in the Museum collection bears no indication of its locality ; we know, however, that Dr. Liitken is satisfied as to certain specimens, at any rate, having come from Guineal. ECHINOMETRA VIRIDIS. Absol. diam., in millim. (?)ll-5 13 15 Percentage value of Height. 347 40-3 366 Actinostome. 521 48 50 Abactinal area. 45-2 20 20 Anal area. 11-3 11-6 11-6 STOMOPNEUSTES. This is an exceedingly difficult genus, and one with regard to which we must have much more information than we possess at present before we can speak at all definitely as to its real affinities. Whatever be the meaning of the " eccentricity " of its test, I must confess that I see no reason, at present, for regarding it as morphologically comparable with that of Echinometra ; for the " tendency to obliquity" is only found in the axis of old specimens, whereas in Echinometra we are informed that the obliquity is " an embryonic feature." W e shall do better to wait for more accurate information than to spend our time in recouciling statements which sufficiently well contradict themselves. I give the figures following for what they are worth ; they prove that great variations obtain in the only species of the genus now known to us. 1 Cf. Zool. Eecord for the year 1873. |