FLORA OF THE WOODBINE SAND AT AETHUKS BLITpF, TEX. 



167 



PhyUites, and in his account of 1874 he sug- 

 gested comparisons with Smilax, Paliurus, 

 and Populus. It has no characters which ally 

 it to Smilajr or Paliurvs, but it is much like a 

 variety of species that have been referred to 

 Populus, the majority of which do iiot present 

 clear evidence to warrant such a reference. 



The species may be described as follows: 

 Leaves rhomboidal to orbicular, with a rounded 

 or cuneate decurrent base, presumably varying 

 to more or less cordate. Apex broadly rounded. 

 Margins entire in their lower halves, undulate 

 toothed in their distal halves. Texture sub- 

 coriaceous. Length about 4.5 to 6 centi- 

 meters; maximum width, midway between the 

 apex and the base, 5 to 6.5 centimeters. 

 Petiole stout, curved, 2 centimeters in length 

 in the smaller leaves, not preserved in the 

 larger. Venation five-palmate from the base, 

 the midrib no stouter than the lateral prima- 

 ries; thej' diverge, at acute angles and arch 

 near the upper margin to join branches from 

 the short camptodrome secondaries. Areola- 

 tion obsolete. 



In foi-m and venation the fossil is much like 

 the modern leaves of both Tefracentron and 

 Cercidophyllum, especially seedling leaves; it 

 is less like Trochodendroii but is approached by 

 seedling leaves of that genus. If, as some 

 botanists believe, these somewhat anomalous 

 vesselless dicotyledons are primitive in their 

 features and not reduced, they should be 

 present among the earlier fossil angiosperms 

 and should show considerable abundance and 

 diversity. The abundance of comparable fossil 

 forms, as I have pointed out, masquerading 

 under various names and widespread and 

 abundant in the closing days of the Lower 

 Cretaceous, in a measure substantiates the 

 first of these assumptions. 



Family RANTTNCXTLACEAE? 



Genus DEWALQTTEA Saporta and Marion. 



Dewalquea insigniformis Berry. 



Dewalquea insigniformis Berry, Torrey Bot. Club Bull., 

 vol. 44, p. 179, pi. 7, figs. 6, 7, 1917. 



Leaves digitate, of probably five leaflets. 

 Leaflets linear-acuminate, with prominently 

 seiTate margins. Length about 12 centi- 

 meters; maximum width mostly 1 to 1.25 

 centimeters, at or slightly above the middle. 

 Base very gradually narrowed and with entu-e 

 margins for a distance of about 2 centimeters. 

 Midrib stout, prominent on the imder surface 



of the leaflets. Secondaries numerous, diverg- 

 ing from the midi-ib at angles of 30° to 40°, long 

 ascending and eventually camptodrome, send- 

 ing oft" small outwardly directed branches to 

 the marginal teeth. Texture coriaceous. 



This characteristic species with its coriaceous 

 texture must have had rather stifi", strict leaves 

 in life. It adds to our flora another form of the 

 curious genus Dewalquea, which is so striking 

 an element in the Upper Cretaceous and lower 

 Eocene. The only known American species 

 that resembles this form in any respect is 

 DcmaJquca smithi Berry, ^^ of the Tuscaloosa 

 and Black Creek formations. D. smithi is 

 much larger, with relatively broader leaflets, 

 which have less j>roniinently serrate mai'gins 

 and partly craspedodrome venation. 



Dewalquea insigniformis is, however, as its 

 name indicates, very much like Dewalquea 

 itisignis Hosius and Von der Marck,-'' a promi- 

 nent species in the Campanian and Maestricht- 

 ian substages of Europe. D. insignis has 

 relatively broader, less pi-ominently toothed 

 leaflets, in some specimens as many as, seven, 

 and the venation is said to be craspedodrome. 

 The venation is, however, a character of slight 

 value, for entire and toothed leaflets gener- 

 ally occur together, and I imagine that De- 

 walquea insignis is merely a serrate form of 

 the associated Dewalquea haldemiana Saporta 

 ami Marion. If the latter liad prominent ser- 

 rate teeth added it would be identical \vith 

 Dewalquea insigniformis. 



Dewalquea insigniformis was described from 

 a large number of fragmentaiy specimens ob- 

 tained in the upper part of the Bingen sand in 

 Pike County, Ark. A characteristic leaflet is 

 present in the early collections from the Wood- 

 bine sand at Arthurs Bluff, Tex. 



Order ROSALES. 



Family CAESALPINIACEAE. 



Genus PALEOCASSIA Ettingshausen. 



Paleocassia laurinea Lesquereux. 



Plate XL, %iu-e 8. 

 Pahocassia laurinea Lesi|uereux, Tlie flora tif the Dakota 

 group, p. 147, pi. 64, fig. 12, 1892. 

 Berry, Torrey Bot. Club Bull., vol. 39, p. 396, 1912; 

 U. S. Geol. Survey Prof. Paper 112, p. 100, pi. 23. 

 fi,s;. 1, 1919. 



Leaflets ovate-lanceolate, subin equilateral, 

 with a pointed apex and a cuneatebase. Length 



M Berry, E. W., Torreya, vol. 10, pp. 3i-3S, flg. 1, 1910. 

 23 Hosius, A., and Von der Marrk, W., Palaeontographica, vol. 2G, p. 

 172. pi. :i2, figs. 111-113; pi. 33. fl^. 109: pi. 34, flg. 110; pi. 35, flg. 123, I8S0. 



