584 ME. LltfSDALL KICHARDSOtf ON [Nov. 1906, 



species, because in the Natural History Museum there is a tablet 

 (G. 6394) with this information on the back : 



' Dentalium tenue, Portlock. Lower Lias Shales, Leckhampton Eoad [Chel- 

 tenham]. E. T.' 



At a later period Tate regarded Dentalium tenue and D. minimum 

 as distinct. He apparently retained Portlock's name for the specimens 

 from the angidata-be&s, and Strickland's for those from the Jamesoni- 

 zone (sic) of Cheltenham. 1 The paper in the Quarterly Journal 

 was published in March, 1870. In September of the same year 

 there appeared, in the Proceedings of the Belfast Naturalists' 

 Field-Club, a communication wherein the name of the angulata-hed 

 fossil was changed from Dentalium tenue to D. Portlocki. The 

 specimen to which this name was applied is in the Museum of 

 Practical Geology at Jermyn Street [7999], and there are two other 

 examples of what appear to be a similar form in the same collection. 



Thus, at the close of the year 1870, Tate regarded the scaphopod 

 from the Jamesoni-zone (sic) of Cheltenham as D. minimum, 

 Strickland, and that from the angvlata-De6\s as D. Portlocki, Tate. 



"Whether Tate ever discovered that the true Dentalium minimum 

 from the angidata-heds was distinct from that which he was at this 

 time identifying with it from the Jamesoni-zone (sic) of Cheltenham, 

 will never be definitely known ; but a hint that he did so may be 

 gathered from the legend on a tablet in the possession of the 

 Geological Society, which reads : 



' Dentalium parvulum, Buckman. Middle Lias, Leckhampton Eoad Clay-Pits, 

 Cheltenham. E. Tate, Esq., F.G.S.' 



When he arrived at this conclusion, namely, that the shell from 

 the angulata-beds was distinct from that from the ' Jamesoni-zone,* 

 and saw fit to employ for the latter a manuscript name apparently in 

 use by James Buckman, it is impossible to say ; but that Buckman 

 considered the forms distinct is obvious. 



In 1876 Tate considered his species Dentalium Portlocki as 

 synonymous with D. etalense of Terquem & Piette. 2 



I have been unable to discover the whereabouts of any types of 

 Dentalium minimum, Strickland-Buckman. There are no specimens 

 answering the description of its author in the Sedgwick Museum, 

 Cambridge ; the Eev. J. B. McClellan, Principal of the Eoyal 

 Agricultural College, Cirencester, writes to me that there are no 

 examples of Liassic Dentaliidae in the museum of that Institution ; 

 and Mr. S. S. Buckman does not know where the type may be. 



The holotype of Tate's Dentalium Portlocki, however, is preserved 

 at the Museum of Practical Geology [7999]. Since no proterotypes 

 of Dentalium minimum can be found and no topotypes can be 

 obtained, and since D. Portlocki and D, minimum certainly seem 

 identical, I have taken for the standard reference Tate's figure of 

 D. Portloclci. Thus the holotype of D. Portlocki becomes the neotype 

 of D. minimum, Strickland-Buckman. 



1 Quart. Journ. Geol. Soc. vol. xxvi (1870) p. 398. 



2 ' The Yorkshire Lias ' 187G, p. 332, and specimens in the Museum of 

 Practical Geology. 



