NO. 8 OPINIONS 124 TO 133 7 



In a letter to Dr. Bather, W. J. Arkell discusses the case as follows : 



Cox's letter to you on the subject of d'Orbigny seems to me to be rather too 

 unconcerned. To say " that our primary object was to obtain a definite ruling ", 

 as if it did not matter much one way or the other, is too mild a statement for 

 my view of the case, so may I give my reasons more fully? 



Dr. Stiles, in the last paragraph of his letter (herewith), says "but in this 

 particular instance it is not clear to me how many names are involved or how 

 much of an upset would occur." At the outset, therefore, I should like to make 

 it clear that I am in favor of the suppression of d'Orbigny's " Prodrome " 

 names, not because of any prejudice against d'Orbigny or his work, but solely to 

 prevent just such an "upset" of a very large number of familiar species. 



I am fresh from trying to compile a monograph of the Bathonian Lamel- 

 libranchs, and it has been vividly brought home to me in the course of this work 

 what a revolution in nomenclature the recognition of the " Prodrome " names 

 would bring about. For the " Prodrome " was published in 1850, and Alorris and 

 Lycett's " Alonograph on the Mollusca from the Great Oolite ", from which 

 nearly all our familiar names are drawn, was published in 1853-4. Morris and 

 Lycett. who described and figured the species so well, very rightly gave up the 

 attempt to interpret the " Prodrome " species, which they regarded as virtual 

 nomina niida. In the few instances where they thought they recognised one of 

 d'Orbigny's species they were always wrong. For instance, Trigonia cassiope 

 [of] Lycett is not T. cassiope d'Orb., which has since turned out to be a synonym 

 of T. piiUns Sow. The original diagnosis was as follows : " Espece voisine du 

 T. Costata, mais plus longue et pourvue sur I'area anale de trois grosse cotes 

 saillantes crenelees independamment des cotes intermediaires : Luc, Vezelay, etc." 

 On this Boule comments in the "Types du Prodrome", IQ13, p. 145: " Cette 

 diagnose a donne lieu a des interpretations diverses. Lycett a decrit et figure 

 sous ce nom des echantillons qui doivent etre pris comme types (Suppl. Mon. 

 Moll. Gt. Ool., pi. 37, fig. 10, et Mon. Brit. Foss. Trig., pi. 32, figs, i and 5). 

 La collection d'Orbigny renferme sous ce nom des echantillons varies ; les uns 

 sont indeterminables, tels que celui de Vezelay, la plupart des autres sont des 

 T. pulhis Sow., ainsi que I'a reconnu j\L Bigot." 



Again, with regard to Myoconcha actacon d'Orb.. Boule writes : " L'echan- 

 tillon de la collection d'Orbigny est tres mauvais ; il faut prendre comme type la 

 figure de .V. actacon- donnee par ^ilorris et Lycett " 



You will notice that in both these quotations there is a tacit assumption that 

 it is only d'Orbigny's type specimen which could give the name validity, but 

 when this has to be rejected Morris and Lycett's species should be regarded as 

 the types. There is no suggestion that d'Orbigny's descriptions should give the 

 species validity. 



If we reject some of d'Orbigny's names on the ground that the type specimens 

 are unsatisfactory', it seems to be introducing an arbitrary factor in the form of 

 personal opinion, and I do not see how anyone is to pronounce finally whether the 

 type specimen of any species is satisfactory or not. An\-one's work is liable to be 

 overturned at any moment by the expression of a diflferent Opinion about the 

 d'Orbigny collection in Paris. I have referred to this collection in a few cases 

 myself, and know- there is plenty of scope for different interpretations. The 

 species in many of the boxes are composite. 



