180 Frederick Cliwpman : 



furnish any definite data as to zonal distribution, so far as 

 can be gathered by comparison with the two widely separated 

 areas of Europe and Australia. As a rule the shells of palaeo- 

 zoic fossils in the Melbourne district are only indifferently pre- 

 served, but a marked exception is shown in Lingula lewisii, 

 var. /Ie/uin(/foneiisis, described below. In that varietal form 

 something akin to the original colour still remains in the shell, 

 accompanied by the du.al structure of corneous and former 

 calcitic layers, the corneous showing undoubted tubulated 

 structure, in confirmation of Carpenter's researches. 



Lingula lewisii, J. de C. Sowerby, var. flemingtonensis, 

 var. nov. (PI. XLV., Figs. 1-5). 



DescrijJfioii. — Tliis variet}^ is comparable in almost every 

 way Avith the type species, the distinguishing characters con- 

 sisting in the slightly broader aspect of the shell and its very 

 distinct, radiate striae. 



L. lewisii is described by J. de C. Sowerbyi as '' Oblong, com- 

 pressed, smooth ; sides straight and parallel.' Davidson, in his 

 '* Monograph of British Silurian Brachiopoda,"2 describes it as 

 with " surface nearly smooth, or marked with numerous con- 

 centric raised lines or ridges of growth, and here and there by 

 more deeply indented striae." ITie figures given by both 

 authors show faint radial or vertical striae. I have examined 

 the shell-surface of two examples of L. lewiaii in the National 

 Museum collection, from Walsall and Sedgely in Staffordshire, 

 and note that the striae thereon are distinct, fine, and generally 

 interrupted by the concentric growth-lines ; whereas in the Vic- 

 torian shells the striae are strong, continuous, and often deeply 

 incised. In point of size the Victorian variety does not quite 

 equal the European species, but is nevertheless by far the 

 largest of the Lifu/ulae in our silurian strata. 



The largest Victorian specimen measures 23 mm. b}^ about 

 16 mm., which is 7 mm. shorter than the English examples 

 recorded by Davidson. The type species ranges practically 



1 In Murchison's Silurian System (1839), Pt. II., p. 61fi, pi. vi., firf. 9. 

 •2 Pal. Soc, 180(5, p. 35, pi. iii., figs. 1-6. 



