ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 673 



possibly account for the great variety of form which Feneroplis tends 

 to exhibit. 



Detection of Polycystina within the Hermetically - closed 

 Cavities of Nodular Flints.* — Dr. Wallich announces the discovery 

 of a number of well-marked Polycystina amongst the loose fossilized 

 contents of nodular flints obtained from the Surrey gravel-pits. In 

 common with other observers he has often noticed minute objects in 

 flint sections, which are, in all probability, the remains of these 

 organisms ; but in no instances were the appearances revealed by the 

 Microscope sufficiently distinct to place their identity beyond c[uestion. 

 In the case of the structures now under notice there can be no doubt 

 of the kind, and we are fui'nished with another interesting link in 

 the chain of evidence which goes to prove the general lithological 

 identity of the chalk with recent deep-sea calcareous deposits. 



The genera of Polycystina met with in the nodular cavities are, 

 for the most part, Astromma, Haliomma (both discoidal and spherical), 

 and Podocyr-tis. A few specimens of well-marked fossilized Dictyo- 

 chidae also occur. Both the Polycystina and the Dictyochidge, as 

 well as the mass of the loose granular material associated with them 

 in the same flint-cavities, are more or less metamorphosed by a slight 

 admixture of peroxide of iron and calcite, the former substance having 

 imparted to the entire structures a bright reddish hue. 



Dr. Wallich has also found, in material obtained from herme- 

 tically-closed flint cavities, by far the most perfectly preserved 

 Foraminifera he has ever seen, the shell-structure and chambers, with 

 every minutest detail of tubular structure, having been converted into 

 chalcedony — the whole mass by reflected light presenting a beauti- 

 fully whitish-blue opalescent appearance, whilst by transmitted light 

 it exhibits a rich transparent burnt-sienna colour, and the well-known 

 fibrous character of chalcedony wherever that substance is most 

 massive, as, for instance, within the chambers. The Foraminifera 

 represented belong chiefly to the genera Botalia, Globigerina, and 

 Textularia. As regards perfection in every minutest detail of shell- 

 structure, these specimens greatly surpass in beauty those meta- 

 morphosed into glauconite, beautiful as they also undoubtedly are. 



Endoparasitic Protista.f —Dr. Grassi has published a full account 

 of his researches into this subject, the preliminary form of which has 

 already been noticed in this Journal.;}; The present paper is much 

 amplified and largely modified from the original : the new views 

 alone will be noticed here. 



Class Flagellata. — Grassi now lays but little weight on the number 

 of flagella as a^classificatory character. He recognizes the following 

 families : — 



1. Gercomonas (sic) Duj. pro parte. Posterior extremity more or 

 less tapering or bifid, several flagella at the anterior end. 



2. Megastomidea Grassi (new), based on Dimorphus muris id,, 



* Aun. and Mag. Nat. Hist., xii. (18S3) pp. 52-3. 

 t Arch. Ital. de Biol., ii. (1882) pp. 402-14. 

 i See this Journal, i. (1881) pp. 764-6. 



