Account of some new infusorial forms discovered in the fossil infusoria from Petersburg, Va., and Piscataway, Md. / by J.W. Bailey.

  • Bailey, Jacob Whitman, 1811-1857.
Date:
1844
Catalogue details

Licence: Public Domain Mark

Credit: Account of some new infusorial forms discovered in the fossil infusoria from Petersburg, Va., and Piscataway, Md. / by J.W. Bailey. 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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    belongs to the Bacillaria, section Naviculaceas. Its members are free and possess a round bivalved siliceous lorica, having three [or more] appendiculated processes, and dividing by longitudinal self-division.” He appears to have seen no fossil species, as he describes none but the P. Germanicus^ which he found alive in sea water at Cuxhaven. Our species may be thus characterized: PoDiscus Rogersi, (figs. 1 and 2.) Lorica large^ orbicular and compressed^ having three to seven hyalme lateral processes placed on an elevated circle^ within which the disc is slightly concave^ and outside of which the surface is part of the frustum of a cone. The whole surface is beautifully punctate, in a man- ner to which no engraving could do justice. The most compli- cated markings on the Coscinodisci scarcely rival the elaborate ornaments of this truly elegant creature. This species is quite common in the fossil state at Petersburg, Ya. and also occurs at Piscataway, Md. Our figure is intended merely to show the general size, and the position of the feet. Pig. 1 shows a view of the disc, and fig. 2 is half of an individual seen edgewise. 2. Zygoceros Tuomeyi^ nob. (figs. 3 to 9.) The remarkable form represented in outline by these figures, occurs both at Pe- tersburg and at Piscataway. I am disposed to refer it to Ehren- berg’s genus Zygoceros, which he describes as being ‘Tree, Na- vicula shaped, compressed and bivalved, each end provided with two perforated horns.” The figures above referred to will give a better idea of the shape of our species than words will furnish, but the following is offered as an attempt to characterize it. Zygoceros Tuomeyi. Lorica having at each end two obtuse horns., with swollen bases, between which are one to three globu- lar projections on each side; those in the middle being largest, and often bearing two spines. At the base of each of the swell- ings the shell often shows perforations, (see a, a, a, figs. 3 and 4,) and the whole surface of the shell is covered with shagreen-like asperities. I dedicate this species to M. Tuomey, Esq., to whom I am indebted for fine specimens of infusorial and other fossils from the neighborhood of Petersburg. Fig. 3 shows a large and perfect individual; fig. 4, a smaller one ; fig. 5, a young individ- ual; fig. 6, one seen obliquely; fig. 7, an oblique view of one half; fig. 8, a top view; and fig. 9 shows two halves of different individuals united in the manner in which they probably formed chains when living.