18 S. S. Buckman — The Genotyiie of Spirifer. 



to occur is constituted by the limestone-plateau, some 7 to 8 square 

 miles in extent, north of the old Yoredale escarpment/ To the 

 south and east of the escarpment the ore occurs usually only in 

 vein-like form, and the existence of large bodies of ore becomes less 

 probable with increased distance from the escarpment and a corre- 

 spondingly increased thickness of cover of Yoredale Beds, which 

 acted as a screen between the iron-bearing solutions and the lime- 

 stone. 



Ore in sojD-like form is also likely to occur in the Limestone 

 beneath the Duddon Sands north of Sandscale, and to a less extent 

 perhaps in the Millom area north of Haverigg. 



In the sop area (excluding the Duddon shores, where exploration 

 is proceeding) the ore-bodies usually come up to the surface, or to 

 the base of the Glacial drift, and presumably most of these (some- 

 where near 100) have been located. Some, however, may have 

 remained undetected in the belt where both sops and " veins " 

 occur most freely — i.e. on the line of the foot of the old Yoredale 

 escarpment from the south-east of Dalton as far as the Lindal- 

 Whinfield district. Moreover, some of the old mines might pay to 

 reopen, for they were abandoned owing to trouble with water or 

 poor demand for ore. 



In the area where the vein-like ore-body is predominant, south 

 and east of the old escarpment, deep cross-cuts may prove reserves, 

 as in one case where not only is an old vein being worked in depth 

 but new ore-bodies have been discovered. 



Brachiopod Nomenclature : The Genotype of Spirifer 



By S. S. Buckman. 



TN this Magazine, August, 1919, p. 371, Dr. J. Allan Thomson 

 -L has an article on the above subject, in which he appears to be 

 expressing the hope that Spirifer cusjndatus may not be taken as 

 the genotype of Spirifer, though he thinks that certain rules of 

 zoological nomenclature drive him to that conclusion. 



It IS all very well for zoologists to draw up rules with regard to 

 nomenclature, but they can get tied up with them ; and then fresh 

 rules must be made to interpret the former, which may go on ad 

 infinitum.. Nowadays in science as in politics we are hung up with 

 too many rules. Rules breed rules, and the worse they are the 

 more they breed. So the fewer rules the better. But there is one 

 rule necessary in nomenclature — read the original diagnosis and try 

 to give efiect to the author's intention, so as to fit it to modern 

 requirements. 



Why is Sp. cuspidatus to be the genotype of Spirifer ? _ Because 

 it is the first species mentioned. That may be denied, but if it were 



1 The course of this escarpment is shown in pL iii of the memoir. 



