246 Scientific Intelligence. 



The JBilobites are considered in the second section of the article 

 and it is concluded that " so far as American examples are con- 

 cerned " the forms referred to the following genera, viz : Rusich- 

 nites Dn. = Rusophycus Hall, Arthrichnites Dn. = Arthrophycus 

 Harlan, Cruziana D'Orb., Climactichnites Logan. Frcena Rouault 

 and Crossochorda Schimper (in part), were the burrows and 

 tracks of marine animals, generally Crustaceans, although some 

 may have been produced by Chsetopod worms. 



Scolithus linearis Hall and S. Canadensis Billings, from the 

 Potsdam sandstone, are worm-burrows, as is clearly shown by the 

 photograph of a slab with characteristic Scolithus markings from 

 Perth, Ontario. A similar origin was assigned to the Fucoides 

 graphicus Van. and F. verticalis Hall, from the Portage sand- 

 stones of New York, by Dr. H. S. Williams in Bulletin No. 41 of 

 the U. S. Geological Survey. The genus Sabellarites is proposed 

 for certain forms, regarded as worm tubes, from the Black River 

 limestone and the Quebec group. 



It must not be inferred that Sir William has rejected all of the 

 Silurian and Devonian fossil algae ; because, there are certain 

 types which he as emphatically affirms are true Fucoids. As 

 examples may be cited Buthotrephis gracilis Hall of the Cambro- 

 Silurian and B. Grantii Dn., from the Niagara group of Canada. 

 Although the distinction between branching plants and branching 

 tracks seems very difficult to the superficial observer, it is stated 

 as a general rule by the author, that " The latter are gener- 

 ally of the nature of more or less cylindrical bodies, diverging or 

 radiating from a common center ; while the former display either 

 alternate ramification or bifurcation." 



Perhaps section VIII, which closes the paper, is the one of 

 most general interest and about which there is the greatest 

 diversity of opinion. The author briefly describes " Pill-marks, 

 as distinguished from animal- or plant-impressions," and mentions 

 " the genera Dendrophycus, Delesserites, Vexillum, Aristophycus, 

 Chloephycus, Tricophycus of authors as examples of genera which 

 contain, or consist of, examples of Rill-marks." Two figures are 

 given of these rill-markings from the Carboniferous of Nova 

 Scotia, which are stated to be " taken from surfaces unquestion- 

 ably sculptured by water," and it appears that one of these, fig. 

 18, is very similar to forms that have been described by Les- 

 quereux and Newberry as Dendrophycus. Recently Professor 

 Joseph F. James has called the Dendrophycus triassicus of New- 

 berry a rill-mark (Am. Naturalist, vol. xxiii, p. ]080), which has 

 called forth a rejoinder from its describer, re-affirming his original 

 opinion (Idem., vol. xxiv, pp. 1068, 1069). c. s. p. 



3. Annual Repjort for 1889 of the Geological and Natural 

 History Survey of Minnesota, N. H. Winchell, State Geolo- 

 gist. — This eighteenth annual report of the Minnesota Survey 

 contains a report of field observations by N. H. Winch ell, made 

 by him and Mr. H. V. Winchell. These include an account of 

 the Mesabi iron range of the crystalline rocks of the Minnesota 

 Valley, the discovery of gold in the Keewatin in northern Minne- 



