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VII. 
OSTRACODA FROM THE CHARA-M.KKL OF HITCHIN. 
By Frederick Chapman, A.L S., F.R.M.S. 
Communicated by John Hopkinson, F.L.S. 
Read at Watford, 23rd April, 1901.* 
The Chara-mnxl or “ fresh-water bed” of Hitchin is so remarkably 
rich in Ostracoda that it appears desirable to put upon record more 
detailed information regarding them than has been attempted up 
to the present time. They have already been referred to in a note 
by Messrs Jones and Sherborn on a collection made by Mr. William 
Hill, F.G.S.f The four species there recorded are Cypris incongruens , 
Scottia Browniana , Erpetocypris reptans , and Candona Candida. 
The same authors subsequently'{ noted an additional species, 
Cypridopsis vidua [ = Pionocypris vidua] ; while for the previously 
recorded Cypris incongruens they substituted Candona pubescens. 
For the material from which the species here enumerated have 
been extracted I am indebted to Professor T. Rupert Jones, F.R.S., 
who had received it from Mr. W. Hill a long time ago. The 
present list contains only one species which I have not myself 
found, and eight species with two varieties are now added to the 
earlier records. 
The bed containing the Ostracoda here under notice lies upon 
a bed of gravel, and is itself overlain by a bed of brickearth 20 feet 
thick. It is a “ soft calcareous loam, of a light colour, from brown 
to almost white, which has been found, in other parts of the 
brickfield, to pass down into a dark grey or almost black deposit, 
fairly evenly stratified.” || 
Besides the Ostracoda this deposit contains numerous stems and 
fruits (oogonia) of Char a, eleven species of Mollusca, and the 
remains of bear, deer, and rhinoceros. 
The sample of marl examined was exceedingly rich in Ostracod 
valves, but they are very fragile and require care in the extraction. 
The process of washing the marl and separating the organisms 
is best carried out by submerging a sieve, containing some of the 
marl, under water, the sieve having meshes fine enough to retain 
the minute fossils; and from time to time agitating the sieve 
vertically as well as in a horizontal and circular direction. 
The following is a list of the Ostracoda from the deposit at 
Hitchin so far as at present known. 
* Abridged by permission from the ‘ Annals and Magazine of Natural History,’ 
ser. vi, vol. xix, pp. 591-597 (June, 1897), which should be referred to for the 
synonymy of the various species and their illustration (on plate xv).— Ed. 
f ‘ Geol. Mag.,’ dec. iii, vol. iv, p. 459 (1887). 
f ‘ Suppl. Monogr. Tert. Entom.,’ p. 12 (Pal. Soc., 1889). 
|| ‘ Proc. Geol. Assoc.,’ vol. xiv, p. 416 (1896). 
