OLDEK I'OTOMAC OF VIHCilXlA AM) .MAKYLAM). 533 



Sequoia cycadoi'sis Kontaino. 



PI. ('IX. KiK. H. 



1S89. Sequoia cijcadopsis Font.: Putoniac Flora iM..iH>jrr. V. S. Gcol. Surv., Vol. 

 XV), p.' 24S.pl. cxii, figs. <), <)a, 10. II, Ma; pi. cxiii, li.us. 1, la, 2, 2a, A. 



This is a well-marked species that is liijilily i-liai-acteristic of the 

 Acjuia Cicck liorizoii. Tliere was ohlaiiicd tVoiii Rosiei's Hhilf a very 

 flood specimen that .shows (he terminal part of an ultimate twiji with 

 a number of well-preserved l(>aflets. The rock matter containing it is 

 somewhat different from tlial showing most of the specimens of Hosiers 

 Bluff, as it is an ash-gray pure clay." 



KOSSII, I'l.A.NTS KliOM KlVKltllAI.K. 



[PI. LXXX. No. 12'.!.] 



In the collections there are four clay casts of small cones credited 

 to the locaUty Riverdale. This locality is a cut on the electric I'ail- 

 road between Hyattsville and Riverdale and about mi(lwa>' tietween 

 these two places. The bed is referred to the Arundel formation. The 

 cones appear to belong to Atlifotaxopsis expanm. This small amount 

 of material is of course not sufficient to determine positively the age 

 of the beds yielding them, t)ut, so far as their evidence goes, it con- 

 firms the assumption that it is Rappahannock or Arundel. The speci- 

 mens were collected by Mr. Arthur Bibbins, three of them on July 1 

 and the remaining one on .Juh- 28, 1896. This last is much larger than 

 the others. It was obtained by Mr. Bibbins on an excursion in com- 

 pany with Professor Ward, to wdiom it was given, and it was deposited 

 by the latter in the National Museum. The others are the property 

 of the Maryland State Geological Siu-vey and l)ear its nmnber, 8248. 



" There is n shade of doubt as to whether this specinjen actually came from R6siei-s Bluff. The locality 

 number, &s ofleii liappens, had become detached and was lost before it was sent to Professor Fontaine. I am 

 sure that 1 collected it myself in the soft clay, and I had trinuned the sides in the field with a knife that I carry 

 for the purpose. 1 had also carefully worked out the impression with the proper tools. Finding it in the 

 collection made by .Mr. White and myself on November 2.5, 1891, without n nuiiibcM-, I wrote the number 

 plainly with a pencil on one of the smooth-cut surfaces, then dry and well adapted l.> he written upon. In 

 this form it went to Profes-sor Fontaine, but the difference in the character of the matri.\ did not escape him, 

 and he made the above note on this fact. It is, indeed, wholly dilfcrent from that of any other specimen from 

 the Rosiei-s BlulT locality, and there is no essential dill'erence in the matri.x of any of the other specimens from 

 this locality. I have carefully compared it with all the other collections described in this paper and it does 

 not exactly agree with any of them, but is much nian r to llial from the 72d Milepost and the bank near 

 Brooke. As this species had previously been found only at the former of tliese last-named localities, it is 

 possible that the specimen is from there. The horizon, however, is the same. -L. F. \V. 



