ECHINOIDEA. II. 21 



cellarise; they are certainh' very peculiar, but iiia>' be eiiibr\onic condilioiis of unknown peclicellarise 

 similar to those he figures for Ph. placenta. As for his remarks on I'liorniosniiKi tenue, I woiild suggest 

 to Dr. Mortensen that the Report on the Challenger -Echini was issued in 1881, and that his memoir 

 was published in 1903; he can scarcely expect genera proposed in 19(13 to have received any recogni- 

 tion in 1881 ». 



It is possible that the geniis Hapalcwma (not Hoplo.toma) cannot be maintained, in which case 

 the onh' species, pclluciduvi, would have to be referred to the genus Araosoma, since its peculiar glo- 

 biferous pedicellarise are evidenth- only a special development of the tetradactylous pedicellaria; of 

 the latter o-enus, as shown bv Dr. de jMeijere. That they are not embryonic conditions of unknown 

 pedicellarite is certain; otherwise, fully developed forms would also ha\'e been found among the not 

 very few specimens seen b\- me, and Dr. de Meijere especialh- would have found them in the very 

 rich material he has had for stud\-. Whether now the genus ! lapalosonia has to be maintained (as I 

 think it has| or not, I certainh- did not den>- the close affinity- of A. pellucidniii with A. coriaceuiii 

 and tessclatuiii because I suggested a separate genus for the former, liut, on the coutrar>-, I suggested 

 a new o-enus for it, because I found it too distantly related to A. coriacntiii and tessflaturii to refer 

 it to the same genus with these species. The use of the word because ir. this place is thus not quite 

 fair, and the same holds good in other instances, thus for example when it is said on the same page 

 as the above: I ha\e nothing to say regarding Dr. Mortensen's sneers at descriptions of pedicellaria;, 

 because the\ do not fit with his classification . My criticism of the description of the pedicellarise of 

 Phorviosonta triiuc (as well as of other .species) given by Professor Agassiz is certainly sufficiently 

 justified b\- the character of that description, as will be agreed, I imagine, by anybody who will take 

 the trouble to read my remarks on that subject (Part I. p. 57). 



That Professor Agassiz could not in 1881 recognize the genera proposed by me in 1903 is 

 self-evident. But, nevertheless, I think the remark to which Agassiz refers here quite justified 

 (Parti, p. 55). After quoting from the Challenger -Echini p. 87 as follows: In the only species of 

 the group of which the Challenger collected a complete series f Phoniiosoma toiuf) there was little 

 difficnltv in recognizing the young as belonging to the adult I continue: We could scarcely wish 

 to find a more pregnant proof of the difficult}- or impossibility of determining Echinids without taking 

 the pedicellaria; into consideration... With regard to the excellent long series of ,Phormosoma>y feniie, 

 there are among the specimens referred to this species b>- Agassiz at all events two different genera, 

 but no genuine Phoniiosoma. h-> Professor Agassiz has now estabhshed a new species of the genus 

 Kaii/pfosoiiia. K. iiidistinctuin A. Ag., on a specimen from the Challenger St. 272, referred to Phor- 

 mosoiiia» tcniic (p. no). I venture to imagine that a more careful examination might have made it 

 possible to recognize this specimen as belonging to a separate genus already even in 1881 ; of course, 

 it would at that time have been impossible to know the name to be proposed by me later on, but 

 the genus really did exist alread\- at that time. It is also worth noticing that this genus is sufficientl\- 

 characterized by its peculiar ambnlacral structure alone, without regarding the pedicellarise and spmes. 

 Professor Agassiz does not deny himself the pleasure of correcting me when mentioning 

 Phormosoma', asterias as the last of the Echinothurids described from the > Challenger.* (p. 86); lam 

 sorrv to have to call his attention to the fact that, since I had already treated all the other .species. 



