OCR Text |
Show 1881.] PROF. F.J. BELL ON THE ECHINOMETRIDSE. 425 STOMOPNEUSTES VARIOLARIS. Absol. diam., in millim. 59 fiO 69 73 Percentage value of Height. 52-5 50 52-1 53-4 Actinostome. 271 31-6 28 26-6 Abactinal area. 16-1 16-6 173 20 Anal area. 8-1 8-6 10-9 STRONGYLOCENTROTUS. In adopting the generic name of Strongylocentrotus, proposed in the year 1835 by Brandt, Prof. Alex. Agassiz has done no more than justice to that eminent naturalist; but this act of justice is accompanied by the considerable reward that it has enabled him to group under one name, for all practical purposes new \ the varied forms which had been distributed among different generic sections under the names, chiefly, of Euryechinus, Heliocidaris, Toxocidaris, and Loxechinus. It is the group which at present contains a larger number of species than any other Echinid genus: fourteen species are recognized in the * Revision ;' to this number I have myself been obliged to add one for the reception of certain specimens from the Straits of Magellan 2; so far as I know, no other zoologist has obtained any representative of a new species. STRONGYLOCENTROTUS ALBUS. Absolute diameter, in millim. 54 75 114 115 Percentage value of Height. 51-8 45-3 43-8 47-8 Actinostome. 27-4 24 219 20-9 Abactinal system. 20-3 18 14 15-7 Anal area. Ill 10-6 9-5 1 The recognition of the name (Strongylocentrus) by Dr. Gray (1855) was, unfortunately, ignored by subsequent writers, and seems even to have escaped Mr. Agassiz. Cf. op. cit. p. 161. 2 P. Z. S. 1881, p. 88. PROC. ZOOL. Soc-1881, No. XXVIII. 28 |