160 



;H()RTKR COXTRIBrTIONS TO GENEKAL C.EOLOGY, l'J21. 



Tliis is 11 species of great geologic range, 

 heiiig recorded from the Jurassic to the Upper 

 Cretaceous. The geogiaphic range is equally 

 extensive, embracing two continents, North 

 Ajncrica and Europe. It is ([uite probable 

 tliiit the species is composite, luit no certain 

 grounds for segregation are apiJiuout. 



Some students may doubt tlie wisom of cor- 

 relating both Lower and Upper Cretaceous 

 fornis with a species which is essentially a 

 Jurassic type, but specific differentiation fouiul- 

 ed merely upon stratigraphy has gone astray 

 so often that in cases Uke the present s3-n- 

 thesis may well precede analysis, and it might 

 be added that this was the view taken l)y IIol- 

 lick" with reference to material from Glen 

 Cove, Long Island, suid by ^'elenovsky " in 

 studying the Cenomanian flora of Bohemia. 



Forms indistiiiguishable from the type of 

 this species occur in both the I'atuxent and 

 Patapsco formations of tlie Potomac group, as 

 well as in the Kootenai, Dakota, Black Creek, 

 Karitan, and Magothy formations. 



Phylum CONIFEEOPHYTA. 

 Genus BRACHYPHYLLUM Brongniart. 

 Brachyphyllum macrocarpum formosum Berry. 

 Plate XXXVI, fisiirol. 



Brachyphyllum macrocarpum Berry, Torrey Bot. Chil) Bull., 



vol. 38, p. 183, 1910 mot Newberry, 1896t; vol. 38, 



p. 420, 1911. 

 Brachyphyllum macrorarpum formosum Berry, iilem, vol. 



39, p. 392, pi. 30, 1912; V. S. Geol. Survey Prof. 



Paper 84, p. 106, 1904; Prof. Paper 112, p. 59, pi. r,, 



fig. 9, 1919. 



Slender elongated twigs, pinnatdy liranched, 

 covered with medium-sized crowded, appresseil 

 leaves, spirally arranged. Leaves hlunlly 

 pointetl, smooth, thick. 



In the consideration of the various specimens 

 whicli have been referred to Brachyj)ln/llum 

 miwroairfium, a very considerable variation 

 within certain fixed limits is at once obvious. 

 This variation is usually one of size, the more 

 slender specimens being at the same time 

 smoother. This characteristic has been fre- 

 quently noted tiy ine and is commented upon 

 in |jrint l)y Knowlton," who in discussing the 



II BoUlck, Arthur, V. S. Oeol. Survey Man. Ml, p. 3S, ISOS. 



" Velnnoviky, Jrawt, Die Oymnmiiwineii dor Wlhmlsrhoii Kriililo- 

 rormntlnli, p. II, pi. 2, (Igs. II 10, 21. IKV,. 



'• Knowlton, K. U., U.S. Oeol. Survey null. 10,1, p. 2V, pi. 4, Unn.U.n, 

 l«00. 



younger forms from Wyoming suggests that the 

 specieson the vergeof extinction becamesmaller 

 in its proportions. In studying the material 

 from the South Atlantic and Gulf .States a con- 

 stant ditrcreiice in size was noticed. This may 

 reflect a slight difference in < liniatic condi- 

 tions, and all the forms may be interpreted 

 as the variations of a single species -in fact, 

 the specimen from the Raritan formation in 

 New Jersey illustrated in Newberry's (igure 

 7"^ is approximately of the same size a.s the 

 forms from the Montana group of the West 

 and is associated with the normal stout, club- 

 shaped type. That the variety ha.s no par- 

 ticular stratigraphic significance is indicated by 

 its abundance at a horizon as low as the ba.sal 

 part of the Tuscaloosa of Alabiuna and its 

 presence in tlie Woodbine sand of Lamar 

 County, Tex. In general the present variety 

 occurs in later and more southern beds than the 

 type, a difference which might be ascribed to the 

 fact that only the slender terminal twigs are 

 preserved. This explanation is regarded as 

 improbable, however, for the same reasoning 

 should hold good for the areas where onl}' 

 thicker twigs have been found. 



The remains are usually much macerated 

 and broken, and the immediate cause for the 

 recognition of a new variety was the discovery 

 of a relatively large specimen from the Magothy 

 formation of Maryland, which showed such 

 striking unlikeness to the typo that separation 

 was demanded and specific differentiation was 

 even considered. In view, however, of the 

 occurrence of both forms in assiM'iation in 

 Maryland and tlie well-known variation not 

 only of the type but of coniferous foliage in 

 general, it seemeil wiser to consider tiie present 

 form as a variety of the type, whicli as time 

 ])rogressed supplanted it to a large extiMil if not 

 altogether. 



Tlu^ new specimen from Maryland showed 

 the lerminal jiait of two approximately 

 parallel and curved lwigsal)out Vl centiinolors 

 in length, united proximad. Those in their 

 largest portion ai(< only 11 millimeters in diame- 

 ter. At intiM-vals of ;{ to .") millimeters sub- 

 opposite lateral branches arti given off in a 

 pinnate manner. Tlu^se are relatively much 

 elongated, curved, and slender, averaging 

 about 4 centimotei-s in length by 2 niillimetere 



■ Nawberry, J. 8., U. 8. Oeol. Survey Mon. 24, pi. 7, nn.i. 1-7, IKiM. 



