ECHINOIDEA. II. 25 



larger form of trideiitate pedicellariæ. In -Pli. Iiispidiiin I have found a kind of opliicephalous pedi- 

 cellaria; this nia\- suggest that opliicephalous pedicellariæ will prove to exist also in the other species 

 of the genus Echinosovia. Agassiz is then evidenth- right in niaking panamcnsc an ally of «/%.» 

 tenue. whereas it is certainly less fortunate to niake <P//.'; hispidiim, xthe Pacific representative of the 

 Carihbean and Northern Atlantic Pli. uiuuiiis , as by the latter is probably nieant not the true Eclii- 

 nosoiiia iirainis. which is not known from the Caribbean Sea, but the Hygrosoniii Pctcrsii. which has 

 hitherto been wrongly called Plioriiiosoina urainis. — Regarding the new species Phofiiinsoina srnlaudicr 

 A. Ag., established on a specimen from the Challenger St. 169, identified as Asfliciiosoiiia gracilefy>, 

 it is inipossible to state with certaint\' to which genus it realh' belongs, since not a word is said about 

 the spines and pedicellariæ; tojudge from the figure given of an ambulacrum (PI. 51. Pig- 3) it ma>' be 

 supposed to be likewise an Echiiiosoiiia. which would be in accordance with the statement (p. 108) that 

 it is allied to ..Pli. hispidtiiii. 



Professors Bell, de Loriol and Laniliert besides Professor Agassiz have also opposed 

 niy classificatory results. Professor de Loriol onl\- remarks regarding the genus Pscndcclunus es- 

 tablished by me for Ecliii/asi albociiicttis Hutton, that he thinks que c'est aller un pen loin que de 

 créer une coupe nouvelle basée sur ce seul et unique caractére (et encore faudrait-il s'assurer qu'il est 

 parfaitement constant), qui ne peut s'observer que sur les exemplaires dont le rexétement est entiére- 

 ment couservé) '. As Professor Doderlein has already (op. cit. p. 231— 3) carefuUy answered these objec- 

 tions, I need only refer to his remarks on the question with which I quite agree. I may however make 

 the more general remark that in the Families Ecliii/idæ, Toxopnciisfida- and Ecliinoinetridæ, the structure 

 of the test is upon the whole ver\- similar, so much so indeed, that it seems impossible in the test 

 alone to find reliable characters even of the families, as is well seen by the manner in which forms of 

 all three families were put together in the genera Ecliimis and Sfrongylocentrotiis. before the charac- 

 ters of the pedicellariæ and spicules were taken into consideration. It almost looks as if, on reaching 

 the high level of development of these forms, nature could not go any farther on those lines, (the 

 Echiiioiiicfridu-, of conrse, form a remarkable exception), and, instead, went on to develop the pedicel- 

 lariæ, especially the globiferous, into very characteristic structures. Be that as it may; ever\body who 

 has studied a large number of the genera and species of these three families, with regard also to 

 their pedicellariæ and spicules, must be struck with the remarkable constancy and characteristic appear- 

 ance of these organs and find it very natural to make them the foundation of the classification, in 

 spite of their being so small that they cannot be seen without careful microscopical examination. — 



De Loriol's remarks (op. cit. p. 16) on my limitation of the genus Stercchinus as well as those 

 of Professor Doderlein (loc. cit.), I cannot answer before I have undertaken a renewed stud\- of this 

 whole group, which I intend to do in m\- Reports of the Swedish and the German South-Polar Ex- 

 peditions. 



Professor Bell in his Report on the Echinoidea from South-Africa-' most decidedly keeps aloof 

 from m\" classification, without giving, however, very definite objections. To his remark that he does 



■ Notes pour servir a l'éUide des Echinodernies. II. Ser. Fase. II. 1904. p. 20. 



' Marine Iiivestigations in South Africa. Vol. III. 1904. The Echinodeniia. Part I. Echinoidea. 



The InB:olf Expedition. IV. 2. 4 



