456 = Prof. T. R. Jones and Mr. J. W. Kirkby on the 
J. & K., but the latter has the greatest height near the 
centre and is suboval rather than subovate. Pl. XXI. fig. 4 
represents a side view of this Cytherella, which we propose 
to name C. tntercalaris. 
Individually the Avrkbye are less numerous than at Hurst ; 
but the genus is represented by an additional species, 
K. spinosa. 
There is an Ostracod from Downholme that we cannot 
place satisfactorily with any described species. It has the 
outline of a Beyrichia or Kirkbya, or some feeble Leper- 
ditioid forms, but with simply convex smooth valves, without 
either pit, furrows, lobes, or tubercles; it is wider and higher 
at one end than the other; one valve (the right, the high end 
being taken as the posterior) overlaps the other on its free 
margins, as in Leperditia. Itresembles Aparchites in outline 
and smoothness, but there is no overlap in this genus. Possibly 
the specimen under notice is an extremely weak Leperditia. 
It is left for the present as a doubtful form. 
At Downholme single valves are met with, not showing 
the peculiar denticulate hinge-line of Youngiella, but in other 
respects (such as minuteness, elongate-oblong shape, straight 
dorsal border, slight obliquity of valves, and faint reticulation 
of the surface) their characters agree exactly with Youngiella 
rectidorsalis, J. & K., the only known species of the genus 
(Pl. XXI. figs. 5a-d). This is the Youngia rectidorsalis, 
J. & K., 1886; but the generic term ‘‘Youngia”’ had been 
already used for a Swedish Trilobite by Prot. G. Lindstrém 
in the ‘ Oversigt k. Vetenskap-Akad. Forhandl.,’ no. 6, 1885, 
p. 49; therefore we have adopted the name Youngiella. 
The Ostracod placed doubtfully as Argillecia equalis, 
J. & K., is very like a somewhat dwarfed individual of this 
species ; but we are not sure about it. It might be regarded 
as a variety of Bythocypris cuneola, J. & K., which already 
contains varieties not unlike it, including similar small forms 
of doubtful affinities. A. equals is essentially a Lower- 
Carboniferous species. Its presence in the Yoredale strata is 
not well authenticated. 
3. Notes on other Carboniferous Ostracoda from Yorkshire. 
As supplementary to the preceding observations we give 
the following list of species from another locality in Yorkshire. 
The Ostracoda from which this list was determined were sent 
to us by Mr. James Bennie, of the Geological Survey of 
Scotland, and were found by Mr. Rhodes, Collector to the 
Geological Survey of England. The locality given is Dow- 
