204' Bibliography. 



5. Rhaphoneis. Has not the orbicular form of those just described, 

 but is quadrangular, navicula-like, not forming chains, and having neither 

 the ribs, lateral aperture, or umbilicus of Navicula, but with the sides 

 marked in the middle with a longitudinal suture. Six species are de- 

 scribed, among which we recognize several forms which are quite com- 

 mon in the fossil infusoria of Virginia and Maryland, as well as in the 

 living state upon our sea-coast. 



6. DiCLADiA. This genus is doubtfully referred to the Bacillaria. It 

 has the lorica, simple bivalve, siliceous, one-celled, not forming chains, 

 valves unequal ; one turgid simple, the other with two horns which are 

 sometimes branched. This genus includes the curious forms of unknown 

 origin which we have represented in Plate III, figs. 24 to 27, Vol. xlvi, 

 of this Journal. 



Besides the account of the new genera, Ehrenberg also gives in his 

 memoir the characters of 140 new species of microscopic Polygastrica, 

 Polythalamia, and Phytolitharia, more detailed accounts of which will be 

 given in his forthcoming volume, a work which will be eagerly sought for 

 by all lovers of this fascinating branch of paleontology. 



It may be interesting to add to the above, that in a letter recently re- 

 ceived from Ehrenberg he gives us the following authentic names of sev- 

 eral of the forms represented in Plate III, Vol. xlvi, of this Journal. 



Figs, Bailey. Ehrenberg. 



1, 2, Podiscus Rogers! = Eupodiscus Rogersii. 



3 to 9, Zygoceros (Biddulphia) Tuomeyi = Denticella tridentata. 

 10,11, Zygoceros rhombus =: Denticella rhombus. 



13, 15, Navicula concentrica = Goniothecium Rogersii. 



24, 27, Bodies of unknown nature = Dicladia. 



29,30, " " " = Rhizosolenia. 



21, Bodies with large cells = Lithocampe radicula. 



J. W. B. 



3. The Botany of the Antarctic Voyage of H. M. discovery ships 

 Erehus and Terror, in the years 1839 — 1843, under the command of 

 Capt. Sir James Clark Ross, Kt., R. N., etc. By Joseph Dalton 

 Hooker, M. D., R. N., F. L. S., Assistant Surgeon of the Erebus, 

 and Botanist of the Expedition. London. Parts 1 — 3. 1844. pp. 48, 

 4to. plates 1 — 25. — The publication of the scientific results of Capt. 

 Ross's voyage, was promptly commenced, and is prosecuted with great 

 vigor. The botanical portion, with which Dr. J. D. Hooker, the botanist 

 of the expedition, is now assiduously occupied, is to appear in monthly 

 parts, until the whole is completed in five volumes royal quarto, with 

 five hundred lithographic plates. It is to be divided into three separate 

 portions, viz. 1st. The Flora Antarctica, which is intended to em- 

 brace a complete history of the vegetation, as far as known, of the 



