660 



PEDICELLARLE. 



out, by MUller, Troschel, Sars, and A. Agassiz, which should have prevented 

 much useless speculation.* No attempt has been made to ascertain the 

 homoloo'ies of these organs, with the exception of a short article in the 

 American Naturalist, intended to give the results which have been reached 

 by the writer since 1864, from the study of the embryology of starfishes and 

 Echini. 



Pedicellarue are. as is well known, scattered in between the spines over 

 the whole surface of the shell. The pedicellaria? consist of a calcareous stem 



* The attempt Perrier makes of applying our knowledge of the pedicellarise to the classification of the 

 collections of the Jardin des Plantes must In- regarded as Bomewhat unsatisfactory. The observations are 

 made on museum specimens, and though the material accumulated is verj considerable, yet do additional 

 information is given on die nature oi the pedicellarise. The omissions from the literature of Echinoderms 

 are such that no critical revision of the subject from a new point of view could l»- made, a- he attempts. 

 In tin- catalogue "i the species no notice has been taken of numerous species of starfishes ami sea-urchins 

 described by Sars, Liitken, Stimpson, Grube, Mobius, Verrill, and A. Agassiz, ami tin- anatomical works 

 relatin" to the subject are incompletely quoted. Tin greater part of what has appeared on pedicellarise 

 ami spiculse by Johannes Miiller, Stewart. Troschel, Stimpson, A. Agassiz, aid Herepath has passed un- 

 noticed, ami the conclusions which present tin' r&sumd of the work, given by the author as his own, are 

 simply confirmations ami additional details of the work of his predecessors, 



A- the starfishes are not particularly to be discussed, I will give onlj a few examples of the manner 

 in which the work has been done, leaving further details to the discussion of the Echini, here more 

 properly in question. Simple inspection iloe- not enable us to distinguish at one bj the pedicellarise, as 

 stated by Perrier, whether a starfish belongs to the group with four or mi h two row- of -inkers. StimpBon 



has given excellent descriptions of starfishes, in which he has made use of the character- derived from 



pedicellarise several years before the present attempt of Perrier. These two statements will show that 

 there remains as original with Perrier, as far as the starfishes arc concerned, all the work of detail lor man} 

 species. We are told thai Stichaster has been established bj Norman. Heliaster helianthua is placed in 



Asteiaeanthion. A-tropecten Mulleri i- credited to Valenciennes. Common West Indian and North 



American species, well described by Liitken and Stimpson, receive new name-. Well-known species from 

 Chili and the Arctic regions share the same fate. Solaster i- said to have no pedicfellarise. In fact, both 

 for starfishes and sea-urchins the museum MS. names attached to specimen- are invariably taken as correct: 

 no critical examination of the specie- can possibly have been made, and the whole \ aluc of the method 



urged by Perrier becomes questionable. We do not know from his observations how far the pedicellarise 



vary in any one species of Starfish or sea-urchin. That they do vary considerably is we'll known ; he 



has admitted nominal species as well defined, from their pedicellarise, which show in several cases differ- 

 ences due either to size and age or to extensive geographical range. No reliable data lor systematic 

 zoology can be drawn from the very laborious researches of Perrier, owing to this lack of criticism, and 

 we must fall back to the older memoirs fur trustworthy information. All that bears on the development of 

 pedicellarise written by Erdl, Sars, Koren and Danielssen, Johannes MUUer, and myself has been ignored. 

 The generalizations regarding the nature of the pedicellarue in the regular and irregular Echini (as 

 understood by Perrier) are not correct. lie corrects Valentin for several errors long ago pointed out by 

 Miiller and Stewart, brings up as new facts (see Valentin 1841, Stewart 18G5) the presence of spicule in 

 ambulacra! tubes. He characterizes as new families the Cidaridae, Diademidae, Echinocidaridae, appar- 

 ently ignorant that Miiller, Peters, and Gray have done excellent work on this very subject. A genus 



