238 PROCEEDINGS OF THE MALACOLOGICAL SOCIETY. 



Romer took no special notice of the '■^ pinguis group " in 1857, but 

 in 1864' he included the species above mentioned in a group for 

 which he proposed the name BemitaiHs^ without referring to the 

 Messrs. Adams, of whose publication he seems to have been ignorant, 

 as he makes no mention of Marcia. 



Tryon in 1884* seems to have been misled by Chenu, for he cites 

 V. tmdulosa as his sole example of Marcia without giving any reason 

 for the selection. 



A. new departure was made in 1887 by Paul Fischer,^ who placed 

 Marcia under Tapes, and gave V. exalhida, Chem., as his example, at^ 

 the same time very properly assigning V. undulosa to Goynpliina. 

 I have not been able to ascertain what led Fischer to select V. exalhida 

 out of all the species mentioned by the Messrs. Adams, but anyone 

 referring to his manual will see that it is given as an example only, 

 and is not definitely stated to be the type. 



JS^o one else seems to have had occasion to notice or allocate species to 

 the Marcia group until 1902, when Dr. W. H. Dall published his Synopsis 

 already mentioned (a?«^<?, p. 234). In this, postponing discussion of his 

 reasons, he formed a new generic group under the name of Marcia, 

 taking V. exalhida as the type, but including as subgenera the Katelysia 

 and Heinitapes of Romer, as well as some assemblages of small fossil 

 shells, but excluding from it the V. pinguis and V. paupercula group, 

 which was an essential part of the original Marcia of the Messrs. Adams. 



The reason for this procedure is given by Dr. Dall in his later 

 memoir, and is stated as follows: "Fischer in his Manuel de 

 Conchyliologie cited Venus exalhida, Chemnitz (which was included by 

 the Adams brothers in Marcia, though it does not agree with their 

 diagnosis, the surface not being smooth), as the type of Marcia, and it 

 is probably best to accept this rather than make another change on 

 account of the discrepancy alluded to, which may have been due to the 

 worn condition of their specimen." * 



The surprising part of this statement is the assertion that Fischer 

 cited V. exalhida as the ' type ' of Marcia. Since this is incorrect, the 

 question at once arises whether Dr. Dall can claim to have fixed the 

 type of Marcia or not. If he had definitely selected V. exalhida as 

 the type of his genus Marcia, with or without reference to Fischer, he 

 would undoubtedly have had a strong claim, but in his own words 

 " he thought it best to accept " Fischer's type, which, as a type, had 

 no real existence. 



Feeling, however, that the case was a peculiar one, I wished to 

 obtain the opinion of a competent authority on nomenclature, and 

 I naturally turned to Dr. W. E. Hoyle, who is a member of the 

 Commission of Nomenclature appointed by the International Zoological 

 Congress. He very kindly consented to consider the matter, and 

 eventually sent me the following as his opinion : " It is quite certain 



1 Malak. Blatt., 1864, vol. xi, pp. 83, 94. 



^ " Structural aud Systematic Concliology," vol. iii, p. 177. 



' Man. de ConchyL, p. 1086. 



* Trans. Wagner Free Inst. Sc, Philadelphia, 1903, vol. iii, p. 1319. 



