254 THE POTOMAC OK YOUNGER MESOZOIC FLORA. 



idea can be gotten from the apparent rarity of the forms found here of 

 their real abundance. Dioonifes Buchiauus, in g-reat abundance, formed 

 nearly all the specimens obtained here. 



Taxodium (Glyptostrobus) Brookense, sp. nov. 



Plate CXXII, Fig. 1; Plate CXXIV, Figs. 3-9; Pl.ate CXXXI, Fig. .''i ; Plate CLXV, Fig.s. 1-3; 

 Plate CLXVI, Figs. 4,7; Plate CLXV^I, Fig. 3. 



The principal stems seen are moderately stout and very rigid, the sec- 

 ondary ones mostly slender and rigid, the ultimate ones usually very long, 

 slender, and unbranched, wide-spreading, often very delicate and thread-like, 

 going off at an angle of about 45°, but from distortion due to pressure fre- 

 quently appearing fastigiate and irregularly grouped ; leaves on the oldest 

 stems elongate-linear, acute, close appressed, on the younger stems all 

 very narrowly oblong, or narrowly elliptical, acute to obtuse, very closely 

 appressed, not distinctly visible without the help of a lens in many cases, 

 all spirally arranged ; the facial leaves usually acute, the lateral ones usually 

 more obtuse and sometimes slightly divergent at the tips and incurved ; 

 midnerves slender and thread-like. 



Locality: 72d mile-post, near Brooke; abundant and in fine specimens. 



This beautiful plant is found in abundance in an interru))ted and thin 

 layer of fine clay along with the best preserved of the Angiosperms which 

 occur at the 72d mile-post, such as Menisperinites, Sassafra.'i, etc. Strange 

 to say, it is not found at the bank on the railroad near by. It evidently 

 had twigs that spread widely in one plane, and some of the twigs indicated 

 an expanse of more than a foot. The shale or clay was very unfavorable 

 for the extrication of the specimens, and many of them were much broken 

 up in taking them out. 



This was the case with all of the largest imprints. Plate CXXII, 

 Fig. 1, gives a form with the ultimate twigs of the maximum thickness. 

 It gives well the original mode of attachment and the expansion of the 

 branches. In most cases distortion from pressure has crowded the twigs 

 together and much disguised their true arrangement. This may be seen 

 in PI. CLXV, Figs. 2, 3, and these figures show also the minuteness of 

 some of the ultimate twigs. They often look like slender threads, the 



