On the nomenclature of the Foraminifera. Pt. III. The species enumerated by Von Fichtel and Von Moll / by W.K. Parker and T.R. Jones.
- William Kitchen Parker
- Date:
- 1860
Licence: Public Domain Mark
Credit: On the nomenclature of the Foraminifera. Pt. III. The species enumerated by Von Fichtel and Von Moll / by W.K. Parker and T.R. Jones. Source: Wellcome Collection.
Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.
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![Red Sea*.” This is a somewhat flat Polystomella, slightly umbonate, with the septal spaces open, rendering the chambers somewhat vesicular and the outline crenulate. It approaches near to the typical P. crispa, and is a common variety. D'Or- bigny has figured a similar form under the name of P. Listeri (For. Foss. Vien. pi. 6. figs. 19-23). 8. Nautilus macellus (two varieties). Page 66, var. a. pi. 10. figs, e-g] var. /3. pi. 10. figs. h-k. “ Recent: Zoophytic concre- tions, Mediterranean.” Var. a is a sub-complanate, slightly unsymmetrical Polystomella : the unequal development of the two faces is an interesting feature. Var. /3 is symmetrical, not quite so flat as var. a, and is lobated in its outline by a periodical irregularity of growth, peculiar perhaps to the individual. Both of these are thin varieties of Polystomella crispa. D’Orbigny has recognized the similarity of his P. Fichteliana (For. Foss. Vien. p. 125, pi. 6. figs. 7, 8) to P. macella,—a simi- larity too close, in our opinion, to allow of any distinction. P. macella, when plano-convex, would be equivalent to the Faujasina carinata, D^Orb. (For. Foss. Vien. p. 194, pi. 21. tigs. 29-31) from the chalk of Maestricht. This variety and other flat Polystomellce are very common in the shallow waters of the Mediterranean and the tropical seas, and have been washed into the sands from the sea-weeds to which they have been attached by their flattest surface. This face often shows the whole coil of the spire, as in Faujasina carinata, D^Orb. A large symmetrical urnbonate variety, near to P. macella, var. «, occurs in great abundance in some of the Subapennine and other Tertiary sands and clays. Polystomella macella is more unsymmetrical than any Oper- culine variety of Nummulite, but not so much so as is the rule in Amphistigma vulgaris {=A.gibba): in the latter the aperture is a large slit nearly all on the more bulging side; whilst in Polystomella macella, when most twisted in its growth, the sep- tal plane and aperture are but little afiected, indeed scarcely more so than in the unequally gibbous Operculina. Both the symmetrical and unsymmetrical Nautiloid Foraminifers delio-ht in complanate varieties; and these are often the more irregular in theii’ growth because of their weak and starved condition. The peculiar twist acquired by the complanate Polystomellce is equalled by that in the Australian Vertebralince, both discoidal and crozier-shaped, which, although showing just the same kinds of variation as they are wont to do in other parts of the world (and m fossil deposits), yet have, one and all, their mouth turned more or less to one side; and in the very flat discoidal varieties the shells are often saddle-shaped. * In scfi-saiifl from shells, given by Spcngler.](https://iiif.wellcomecollection.org/image/b2234407x_0009.jp2/full/800%2C/0/default.jpg)
