Apkil 3, 1885.] 



SCIENCE 



281 



in vegetable paleontology will perhaps regard 

 as still more important the discover}- and care- 

 ful characterization of the twenty-eight forms 

 which the author describes, as wholly new to 

 science, twenty-six of which receive the rank 

 of species, and for the satisfactory classifica- 

 tion of which he has found himself obliged to 

 create the two new extinct genera, Merten- 

 sides and Pseudodanaeopsis. Of these twenty- 

 six new species, eight are allied more or less 

 closely to known forms, leaving eighteen spe- 

 cies so distinct that the author has been un- 

 able to compare them with any thing that has 

 been hitherto described. This is remarkable, 

 in view of the great uniformity which is gen- 

 erally found to exist in the floras of the earlier 

 geological formations at points the most widely 

 separated geographically. It seems to indi- 

 cate an unexpected divergence of the meso- 

 zoic flora of North America from that of 

 Europe and other districts of the eastern 

 hemisphere. 



An important feature of the work, not indi- 

 cated b}' its title, is a careful revision by Pro- 

 fessor Fontaine of the researches in the same, 

 line of Dr. Ebenezer Emmons in North Caro- 

 lina, made some thirty }~ears ago, and pub- 

 lished in part vi. of his 4 American geology,' 

 1857. The fossil plants found by Dr. Em- 

 mons, and figured in this work, are described 

 under the head of ' Fossils of the trias ; ' but 

 Professor Fontaine thinks he has conclusively 

 shown, from a study of his figures and descrip- 

 tions (the fossils themselves having been de- 

 stined during the war) , that this ' trias ' of 

 Emmons in North Carolina is identical with 

 his 4 older mesozoic ' of Virginia. 



The work is copiously illustrated, there be- 

 ing, in all, fifty-four plates, the last six or seven 

 of which are devoted to the reproduction of 

 the figures of Emmons. The photo-engraving 

 process is employed, and we have here a stand- 

 ard from which to judge of its applicability to 

 the illustration of fossil plants. In some re- 

 spects it proves quite satisfactory ; at least, 

 when we consider' its cheapness, and the ad- 

 vantage it thus furnishes of allowing, at mod- 

 erate cost, the ample illustration of species, 

 which is so great a necessity in this branch of 

 paleontology. But we do not think the most 

 has been made of the process in the present 

 work. 



The index, which is otherwise good, con- 

 tains one feature which cannot be too highly 

 commended to authors of such works. This 

 is the reference to plate and figure, as well as 

 to page ; which, in more than half the cases, 

 saves the reader the labor of looking twice. 



ANNALS OF THE NAVAL OBSERVA- 

 TORY. 



During the period covered by the observa- 

 tions contained in these two volumes, the 

 naval observatory was under the superintend- 

 ency of the late Rear-Admiral Rodgers. His 

 general reports to the chief of the Bureau of 

 navigation, on the work of the institution, 

 were promptly issued in the latter part of the 

 years to which they refer, and are reprinted, as 

 customarily, in the annual volumes. 



Pursuant to its polic}~, inaugurated some five 

 years ago, of reducing the size of its bulky 

 publications, — a policy which has met with 

 universal commendation, — the observatory 

 might now go farther, and expunge a good 

 fraction of the protracted and annually reit- 

 erated introduction to the observations with 

 the transit-circle. We seriously question 

 whether disastrous ambiguity would ensue if 

 we were not told, with every year, that the 

 ridge of the roof covering the transit-circle 

 extends east and west ; and that the hole in 

 the cube of the axis of the instrument is 2.3 

 inches in diameter; — to say nothing of the 

 continued reprint of formulae and details of 

 reduction, which every astronomer, who has 

 occasion to consult the volume, keeps con- 

 stantly in mind. This introduction now occu- 

 pies about one-fourth of the entire volume, 

 including observations with all the instruments 

 of the establishment, and the several appen- 

 dixes. We suspect, however, that the only 

 sufficient remedy lies, not in excerption, but in 

 rewriting ab initio, on the supposition that 

 those who will read the introduction already 

 know something. 



The newly adopted form in which the obser- 

 vations with the transit-circle are published 

 seems to have been very carefully studied, and 

 is in every way a model. We should like to 

 be able to write as strongly of the precision of 

 the results of stellar and planetary observations 

 with this instrument, the character of which is 

 toow r ell known to require characterization here. 

 Presumably, no one is responsible for the fact 

 that they are not better ; but certainly the fre- 

 quent change of observers, unavoidable in so 

 far as the observatory itself is concerned, is 

 not conducive to results of a high order of 

 accuracy. 



During the years 1879 and 1880. the transit- 

 circle was under the charge of Professor 

 Eastman, and was employed with customary 



Astronomical and meteorological observatio?is made during 

 the years 1879 and '1880 at the U. S. naval observatory. 2 vols. 

 Washington, Government, 1883-84. 



