JUKES-BROWNE : ON SOME QUESTIONS OF NOMENCLATURE. XOI 



but this only makes it the more necessary that it should come before 

 properly qualified committees for settlement. 



2. Glycymeris v. Pectunculus. — The next instance of a name 

 that seems to call for international settlement is that of Pectunculus^ 

 which is intimately associated with those of Nucula and Glycymeris. 

 Both the names Pectunculus and Glycymeris had been variously used 

 by different writers before 1758, but the first binomial author who 

 used the names seems to have been Da Costa, in his " British 

 Conchology " (1778). This fact was pointed out by Dr. Dall in 

 1898 {op. cit, p. 571). 



Da Costa used the name Pectuncuhis for the group of shells already 

 called Venus by Linnaeus, and he applied the name Glycymeris to 

 those members of the Arcid;:e which have a curved or bent hinge-line, 

 as typified by the Area glycimeris and the A. nucleus of Linnseus. 

 In 1799 Lamarck, apparently being ignorant of Da Costa's use of the 

 two names, gave the name Pectunculus- to Area glycimeris, and that of 

 Glycimeris to the shell now generally known as Panopcea, at the same 

 time separating the Area nucleus as the type of a new genus Nucula. 

 It seems clear, therefore, that Lamarck had no right to use the names 

 Pectunculus and Glycimeris in the way he did, because they were pre- 

 occupied by Da Costa ; and, further, that the name Pectunculus, if 

 available at all, can only be used for some sub-division of Venus. 



Lamarck, however, had a perfect right to separate the two Linnaean 

 Arcce, and to make them types of the two new genera, but if we 

 accept the Nucula of Lamarck, the Glycimeris of Da Costa must 

 remain for the Area glycimeris type. Thus, by a slightly different or 

 more expanded line of argument, I come to the same conclusion as 

 Dr. Dall, and need only add that PoU's name Axincea (1795) is long 

 antedated by Da Costa's, even if Poll's generic names could be 

 accepted. 



3. Modiola v. Volsella. — The next and last case that I wish to 

 discuss is one on which opposite opinions have quite recently been 

 expressed, and for which the decision of an international tribunal, or 

 at any rate of an Anglo-American committee, is urgently needed. 



The question is whether the Modiolus or Modiola of Lamarck 

 (1799) ought to give way to the Volsella of Scopoli (1777). The 

 Committee of this Society, which is responsible for the revised list of 

 British Marine MoUusca, retained the name Modiolus in the first 

 issue of the list (1901), but in their supplementary report of 1902 

 they recommended that the name Volsella should be substituted, 

 having evidently been converted to this opinion in the interval. The 

 point on which this question depends is a curious one, and can only 

 be decided after a fair consideration of the circumstances of the case. 



