KOSALES. 



-2-2: 



A (Ictailtul comparison with similar «>xistmg 

 and fossU Mimosaccnv oan tlii'ow but littlo 

 light on the ooology of this fossil form. 



Occurrence. — Lagiango formation (in IxmIs of 

 Wilcox age), Purvoar, Henry County, Tcmi. 

 (collected by E. W. Berry). 



Collection. — U. S. National Mustnnu. 



MiMosiTES vakiahiijs Berry, n. sp. 

 I'latf XI A', tigiiri'sG-ll. 



Description. — Leallets of different sizes, elon- 

 gate-elUptical or lanceolate in outline, as a 

 rule markedly inequilateral, hut this feat in e 

 is only slightly dcvelopi'd in soin(> narunv 

 leaflets. Length ranges from 6 millimet.ei-s 

 to 3 centim(>tors, averaging alxiut 1.6 ccnti- 

 metei-s. Maxinnun width ranges from 2 to 

 7.0 niilhnietcrs. a\'eraguig ahout .j miUinu^ters 

 m the middl(> part of the leaflet. Marguis 

 ontir(>, more or li'ss ]iarallel, curving inward to 

 form the generally similarly ])oiiited ape.x and 

 base. In aU the numei-ous s|)ecimens the 

 lamuia is narrower and more acute at both 

 the apex and the base on one si(h' anil broader 

 and more i-ounded on the other. If any t lung 

 the upper |).nrt of the leaflet is slightly luxr- 

 rower than the lower part. Fi-tioles are inva- 

 riably present, but those are short and stoxit, 

 not over 1.5 millinu>tci's hi length, rugosely 

 ■ftTinkled and as a iide nmch cmAcd. Midrib 

 relatively veiy stout thi-oughout its lengtli, 

 rath(U" promuicnt on the lower sm-face of the 

 leaflet., sti'aight or oui-ved. Si'condary vena- 

 tion obsolete on both siu-faoes of the leallets 

 Ui all exci'pt. the largest s])ecimens, iii wliicJi 

 rather numerous thhi secondarii's diverge from 

 the midrib at angles slightly more than 15°. 

 Texture smooth and ver\' c.<u-iac(>ous. A spec- 

 imen from I'uiyear shows a row of six closely 

 placed leaflets. 



This s])ecies is chai act eristic aiul c-.ommon 

 at several localities and (unbraces both the 

 laigest and the snuxlU>st Wilco.x leaflets of 

 Mhnosit(>s. It is in many ways very similar 

 to the other Wilcox species of Mimositi's, but 

 may be distmguished by its thicker textm'e 

 and obsolete venation. .Uintositcs inequilat- 

 eralis Beny has a c.onspicu(msly rounded apex 

 junl generally a roimded base and a shorter 

 petiohde. .]fimositcs spaiulatus Berry also has 

 a rounded apex and the leaflets arc sessile, and 

 both Mimosites acaciafolius Berry and Alimo- 



sites lanceolatiu'i Berry have sessili- leaflets, ami 

 l(inceolatus is equilateral or nearly so. 



Tliis and the preceding species of Mimosites 

 represent forms mostly identified as species of 

 -Veaeia (as, for exam])le, in the paleol)otaiuc 

 work of lleer, Ettingshausen, and other (Mui- 

 nent students^ which may be properly referable 

 to Acacia or Mimosa or to other genera of the 

 Mimosaceiv — in other words, forms which are 

 referable to this family with great certainty but 

 wbose exact generic alignment is more or less 

 uncertain. Among these I might mention 

 Acacia iinincrci folia described l)y Engelhardt ' 

 from the Tertiaiy of Bolivia aiul compared with 

 the phyllodes ol the modern ^[caeia parailo.m 

 DeCandolle. The Wilcox sp(>cies represents 

 a leal!(M of a compound leaf and not a ])hyllode, 

 and it may he that this is also the nature of 

 Engelhard t's s])eeies. 



Both Acacia and Mimosa are very large 

 genera in the existing flora. Acacia containing 

 more than 400 and Mimosa niore than ;il)() 

 species. Acacia is larixely African and Au>~tra- 

 lian but is fouiul through Oceaniea, South and 

 Ceivtral America, and the West lndii>s. Mi- 

 mosa, on tlie other hand, is mostly coniined to 

 tropical and suhtrojiieal .Vmerica, though a few 

 species live in Asia, .Vfrica, and Australia. 

 Since the Eocene flora of southeastern North 

 America is made up to such a large extent of 

 ancient types, still chiefly .\merican, it would 

 seem that Mimosites as used in this paper iiuli- 

 cates a more probal)lc allinity with Mimosa 

 tlian with Acacia. 



Miniositts variabilis may be compared with 

 numcious existing American species of Mimosa. 

 Among the described fossil s])ecies it suggests 

 3fimosites palwoyxa l'ngt>r,-' M. haeringiami 

 EttingshauseTi,' .1/. cassiseformis Ettmgshan- 

 sen," and Acacia sot::hiHna X^nger.^ 



Occurrence. — Grenada formation, Ciicjuula, 

 Cirenada County (collected by E. N. Lowe aiid 

 E. W. Berrv) , Holly S]irings sand. Early Grove, 

 Marshall County, Miss, (collected by E. W. 

 Berry). Lagrange formation (in beds of Wil- 

 cox age), Furyear, Ilciuy Ciumty, Torn, 

 (collected by E. W. Berry); \\ miles west of 



'Engelliardt, Hermann. Naturwiss. Qiwcll. Isis in Dresden Abh., 

 lS94,p. 11, pi. l.figs. 10,11,20, 



■ EttinKsliausoJi, C. von, I'io terliiiro Florji vou Ujiring in Tirol, p. 92, 

 pl.30.n;;s. 21,22, 1S53. 



= Idem, ngs. 23-37. 



' Idem, figs. 38-50. 



' Idem, Dgs, 55, 50. 



