Upj)er Cambrian Limestone. lOO 



From the Lower Cambrian of the State of New York, Walcotf^ 

 obtained a leperditioid form {Ltperditia dermato'ules), having a 

 punctate surface, which, as Walcott suggested, might represent a new 

 genus. Subsequently, L.dennafoides was made the type of the- 

 genus Indiana bj G. F, Matthew. 2 It was to this species that coim- 

 parison of a South Australian form from Curramulka was made by 

 Prof. Tate, 3 but which is probably referable to a species of Isochi- 

 Una. 



The Ltperditia troi/ensis of Ford,* from the Middle Cambrian of 

 New York State, is now referred to the phyllocarid genus Aris- 

 tozoe, by C. D. AValcott.5 



It is a striking fact with regard to two Leperdifiae now recorded 

 from South Australia, that they rep-resent southern hemisphere 

 forms of two distinct types of the genus, both of which are found in 

 Canada, namely, a short suboval form, like L.anna, and another,. 

 subrhoml:oidal and oblique, resembling the species described as 

 L. canadensis. 



The form here referred to Jsochilina, was relegated to that genus 

 only after some consideration. However, the apparently equal 

 valves and grooved and flattened edges are more in keeping with the 

 characters of this genus rather than with other related generic 

 forms, although it may have later to be given a new genus name. A. 

 very useful list of the known Isoehilinae is given by Prof. Rupert 

 Jones in the Geological Magazine.^ 



DESCRIPTION OF SPECIES. 



OSTRACODA. 



Fam. Leperditiidae. 



Genus Lepepditia, Rouault. 



Leperditia tafei, sp. nov. (Plate IX., Figs, la, b, 2«, 6, 3a, b). 



Description.— Car a,Y)8iCe seen from the side nearly semicircular 

 to suboval; height about two-thirds the length. Dorsal line straight 

 or slightly curved; both extremities bluntly rounded, the anterior 

 forming almost a right angle, bearing a flanged margin. Median. 



1 U.S. Geol. Surv., 10th Ann. Rep. (1888-9), 1890, p. 626, pi. Ixxx., fi^'s. 1, la. 



2 Canadian Record of Science, vol. viii., 1902, p. 460. 



3 Trans. R. Soc. S. Austr., vol. xv., 1892, p. 187. 



4 Amer. Journ. Sci., ser. 3, vol. vi., 1373, p. 138. 



5 U.S. Oeol. Surv., Bull. No. 30, Second Contr. Canih. Faunas N. Anier., p. 146. pi. xvi.^ 

 fitf. .5. 



6 Geol. Mair., Dec. 1 (n.s.), vol. x., July, 1903, pp. 303-304. 



