lUiA.MXALES. 



283 



County), Miss, (collected by E. W. Hil<2;iinl 

 and I']. W. Jicrry ). Lasimni^c formation (in ImmIs 

 of Wilcox a;.;c), Purycar. Ili'iiiy County. Tcun. 

 (collected by K. W. IJeriyi. 



Collfcfioiis. — r. S. Xalional Museum. 



KlIAMMS .MAHCINATIS A I'lCCL.VTUS BoiTV, 



n. var. 

 PUur I.XIX, fi-urc ]. 



Dfsmpfion. — Leaves soinewiiat smaller than 

 the tvjie, lanceolate to oi>l()n;j;-ellli)ti(al and 

 somewlial in"(|uilateral in general outline, 

 widest nudway Ix-tween the ape.x and the base, 

 tajiering equally distad and jiroxiniad. and 

 narrowlv to widely cuneate at the l)as(\ .Vpex 

 abi-uptly narrowed and then extended as a nar- 

 row cuspidate acumen, which is 5 to 10 milli- 

 meters in length and 3 to 4 millimeters in 

 width at the base. Length of leaf ranges from 

 8 to 10 centimeters. Maximum width ranges 

 from 1.8 to 4 centimeters. Margins entire. 

 Texture apparently coriaceous, hut the leaf 

 substance is not thick. Petiole short anil stout. 

 much enlarged proximad, ranging from 4 to 8 

 millimeters in length. Midrib very stout and 

 prominent, as a rule slightly curved. Second- 

 aries stout and very prominent, numerous, 

 regularly spaced, and subparallel: they diverge 

 from the midrib at angles ranghig from 20° in 

 the narrowly lanceolate forms to 55° in the 

 elliptical forms, curve regularly upward, and 

 become parallel with the margins and run prac- 

 tically on them in their camptodrome endings. 

 Tertiarics of the typical Rhamnus type — very 

 thin, close set and subparallel, percurrent at 

 api)roximately right angles to the midrib. 



This forar is clearly marked in some of its 

 features from the tyY>c, ]jut in others the two 

 are identical. In texture and venation they 

 show no appreciable differences. The char- 

 actcre that serve to distinguisli the present form 

 are its greatly shortened petiole and its greatly 

 extended, cuspitlate tip. The variety is smaller 

 than the type and relatively as well as actually 

 shorter. It is common in the Wilcox dejiosils 

 at Hurleys. 



Occurrence.---Ackcnnnn formation , llurlevs, 

 Benton County (formerly part of Tippali 

 Count}-), Miss, (collected l)v E. N. Lowe and 

 E. W."^Berry). 



Collection. — U. S. National Museum. 



KuAMXlT.s ci.EnuHXi Lesfpiereux. 



lUiniiiinis ('kbiirni. Lescnicrcux, U. S. Gool. and'Gcog. 

 Surv. Terr. Ann. Rcpl. for l,S72, ji. 381, 1S73. 

 Li'S(|ueroux, The TiTliarv llora, ]). 'iSO, jil. .53, fins. 



1-3, 1878. 

 I,('s<|uert'ux, U. S. Xal. .Mils. I'n.r.. vol. 11, ].. 24, 



INNS. 



Kiii.wll.in, U. S. CiiMil. Sur\<-y I'.ull. 20!, p. 8i). l!)!).'. 



Description. — Leaves medium sized or large, 

 lanceolate in general outline. Apex and base 

 about (equally jxiintcd ; base in some specimens 

 cuiieale instead of acuminate. Length uni- 

 foi-mly about 11 centimeters in a large num- 

 bci' of s|)ecimens. Maximum width, at or 

 slightly Ixdow the middle, ranges from 3.6 to 

 6 centimeters. Margins entir(\ Texture sub- 

 coriaceous. Petiole rehitively long, stout: 

 length al)(>ut :i centimeters. Midril) stout, 

 prominent on the lower surface of the leaf. 

 Secondaries numerous, tlun but prominent ; 

 about 12 alternate pair's diverge from the mid- 

 rib at angles of 40° to -45°, pass upward in gen- 

 tle, regular, subparallel cui'ves, and are camp- 

 todrome close to the margins. Tertiarics thin, 

 close-spaced, percurrent, well shown in Les- 

 cpiereux's figured types and clearly shown in 

 the specimen from Louisiana, which is jirc- 

 served ui a coarse calcaj'cous sandstone. 

 , This species is represented by a single char- 

 acteristic specimen from Mississippi, by a single 

 nearly complete specimen from Lcniisiana, and 

 by material from Grenada, Miss., which agree 

 in all respi'cts with the material from Colorado 

 and Wyoming. The nu^terial referred by llol- 

 lick to Bhamnus clehunvi is not that species but 

 differs in the characters enumerated mider the 

 discussion of Rhainnus cousiiatta, the name I 

 have assigned to llollick's species. 



BJidninvs mun/iiiatus Lesquereu.x and Rharn- 

 n us (oligniticiif: Berry, two of the ot her species of 

 Rhamnus kno\vni iu the Wilcox, are readily dis- 

 tinguishable from the present species. RJinin- 

 nus eoUgniticus: is common in the flora of thi^ 

 Denver formation at Golden, Colo., and is rare 

 in the Eocene at Black Buttes, Wyo. (accortling 

 to Lcsrpuu'eu.x). It has been recorded from 

 Cherry Creek, Oreg., liy Knowllon ' and from 

 Utah. It is apparently rare in the Wilcox. 



Occurrence. — Wilcox group, Campbell's (piai- 

 i-y. Cross Bayou, Caddo Parish, La. (collected 



' Knowlton, F. H., C S. Geol. Survey Bull. 204, p. 80, 1902. 



