Vol. 58. ] PROF. GROOM ON POLYPHYMA LAPWORTHI. 83 
. On Porypuyua, a New Genus belonging to the Lyerrpitiapn, 
From the CaMBRIAN SHALES of Matvern. By Prof. Turopor: 
Groom, M.A., D.Se., F.G.S5. (Read December 4th, 1901.) 
[Puats ITT.] 
I. OccURRENCE. 
THE number of lobulated ostracoda at present recorded from the 
Cambrian formation is very small, and the species are still very 
imperfectly known. Forms referred to Beyrichia have long been 
known from the Cambrian beds of Scandinavia,’ Stockingford,* and 
South Wales. The writer some time since detected in the lowest 
portion of the Malvern Black Shales a species identical with the 
Stockingford form, which latter had been provisionally identified 
with the Swedish Beyrichia Angelini, Barr. The specimens obtained 
from the Stockingford Shales were few and imperfect; the Malvern 
examples are far more abundant and, though for the most part 
imperfect, are better preserved. ‘They present characters which 
serve to separate the species from those now placed under the genus 
Beyrichia. Mauy of the specimens have been submitted to Prof. 
‘T. Rupert Jones, who (after an examination ee made of much of 
the material) considers it impossible to refer the form to any known 
gnus, and recommends the establishment of a new genus and 
species. I would propose to describe the species under the name of 
Polyphyma Lapworthi. 
The specimens were obtained from the Black Shales (M 257) at 
the northern extremity of Chase Knd Hill, in the Southern Malverns, 
where they were associated with Acrotreta sp., Kutorgina pusilla, 
Sars, Protospongia fenestrata, Salter, and other fossils. ‘The 
shales are nowhere actually exposed, and can be reached onlv 
by excavation. Some two days’ work with the pick and spade 
produced perhaps a hundredweight of the shale in small pieces. 
Polyphyma is very abundant in certain bands of the shale, and 
altogether over 300 recognizable individuals were obtained, in 
addition to many fragments. The shales have been subjected to 
considerable pressure, consequently the specimens are frequently 
crushed and indented, and present differences in their appearance so 
extraordinary that Prof. Rupert Jones and myself at first thought that 
we mnight be dealing with several distinct species. In many examples 
the shell presents a beautifully reticulate appearance; but closer 
1 J. Barrande, ‘Syst. Silur. du Centre de la Bohéme’ vol. i, Suppl]. (1872) 
p. 489. 
2 * C. Lapworth, Geol. Mag. 1886, p. 321. 
* T. Rupert Jones, i/id. 1881, p. 343. Beyrichia Hollit, Jones, is here recorded 
from the Menevian, and regarded as an ally of B. intermedia, Jones (a form 
since referred to the genus Kledenia) : see Jones & Holl, Ann. & Mag. Nat. Hist. 
ser. 5, vol. xvii (1886) p. 362 
G2 
