NO. 8 t)I'IXIOXS 124 TO 133 13 



clatural consequences of zoological assumptions. It is, lor example, 

 entitled to say to a zoologist; " If you honestly believe that Cidaris 

 ivissmanni Desor, 1846. is the same species as Cidaris spiuosa Agas- 

 siz, 1841, you must, other things being equal, adopt the name Cidaris 

 spiuosa." 



Now it is on zoological grounds that Messrs. Cox and Arkell base 

 their application. They say of the new names for previously unde- 

 scribed species in the " Prodrome " ". . . . in each case .... a brief 

 comment is made on the species, but this .... is quite inadequate 

 as a specific diagnosis." This apparently means that the applicants, 

 whose expert knowledge must be admitted, are unable to recognise the 

 species from d'Orbigny's sentences. They are entitled to their opinion, 

 and justified in applying the Rules accordingly. The names will, so 

 far as Messrs. Cox and Arkell are concerned, be invalid. But, as they 

 point out, this will not stabilise the nomenclature, for other experts 

 may hold a contrary opinion. Further, they say, the application of the 

 Rules will result in upsetting a considerable number of names in cur- 

 rent use. This must, it appears, be the result whatever view be held 

 as to the validity of the names, and they claim that the only way to 

 avoid both instability and confusion is to make the names nonavail- 

 able. This can be efi:"ected only by suspension of the Rules. 



A specific instance of the difficulties may lie given : Trigo)iia cas- 

 siope d'Orb. (" Prodrome ", vol. i, p. 308). 



Lycett (1863) took over this name without comment and described 

 British specimens as T. cassiopc d'Orb. Others, however, have inter- 

 preted d'Orbigny's diagnosis differently. 



Reference to the original specimens shows that, in the words of 

 M. Boule, " La collection d'Orbigny renferme sous ce nom des echan- 

 tillons varies ; les uns sont indeterminables .... la plupart des autres 

 sont des T. pnUus Sow." (1913. " Types du Prodrome ", y>. 145.) 



It is open to Professor Boule to say that T. cassiopc d'Orb. cannot 

 be recognised from the description, and so to regard the name as 

 invalid ; or it is open to him to say that T. cassiopc d'Orb. is a synonym 

 of T. puUns Sow. But he continues; " Lycett a decrit et figure sous 

 ce nom des echantillons qui doivent etre pris comme types." Clearly 

 they cannot be the types of T. cassiopc d'Orb., for they were not 

 part of d'Orbigny's material. Is then the name T. cassiopc Lycett 

 available? Certainly not if 7\ cassiopc d'Orb. is recognisable as a 

 synonym of T. pulhis for then T. cassiopc Lycett is a homonym of 

 later date and is to be rejected under Article 35. 



But if we admit Professor Boule's other conclusion that T. cassiopc 

 d'Orb. is unrecognisable, then it cannot l)e said definitely to represent 



