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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    6 3. Zygoceros rhombus? (figs. 10 and 11.) Our figure repre- sents a species which so closely resembles the Z. rhombus of Ehrenberg, that I am inclined to consider it as most closely allied tOj if indeed it be not a variety of, that species. Ehrenberg thus describes Z. rhombus: “ Large, lorica turgid, viewed laterally rhomboidal and having rounded angles, surface marked with very delicate stries, the back having a smooth central zone.’’ These characters apply pretty well to our species, with the exception that the central zone in ours is quite distinctly striated, with two sets of lines crossing each other at right angles. The shape of the horns is also somewhat different in our species from those shown in Ehrenberg’s figure. The Z. rhombus was discovered by Ehrenberg alive in sea water at Cuxhaven; our species is very abundant in the fossil state at Petersburg, Va. To the genus Zygoceros I now unhesitatingly refer the living species which I detected in Boston harbor, and which I descri- bed by the name of Emersonia elegans. I propose therefore to change this name to that of Zygoceros Emersoni. My Emer- sonia antiqua (fig. 25, PI. II, of Bacillaria) is probably only the young state of Z. rhombus ? abovementioned. The living spe- cies form zigzag chains. 4. Triceratium spinosum^ nob. (fig. 12.) This large and very curious species of Triceratium occurs sparingly at Petersburg, Ya. Its lorica is triquetrous, laterally slightly convex, with obtuse an- gles or horns, the surface marked with shagreen-like projections, and bearing four [or more ?] large spines. Fossil with several other species of Triceratium at Petersburg. The figure shows the outline of half of an individual. 5. Navicula ? concenirica, nob. I give this provisional name to the bodies represented in figures 13, 14 and 15. When seen laterally they show an elliptical figure, marked with concentric circular spaces, which when seen edgewise are found to bound a series of gradually diminishing step-like projections. Two indi- viduals [?] probably resulting from spontaneous division, are usu- ally found adhering. Fossil at Petersburg and Piscataway. Fig. 13 shows an edge view, fig. 14 the side, and fig. 15 an oblique view, with the end to the front. 6. Dictyocha fibula? (fig. 16.) This occurs in vast abun- dance among the fossil infusoria at Piscataway, Md. It differs from Ehrenberg’s D. fibula^ by generally having five instead of