COMPOSITION OF THE FLORA. 



95 



and luil)it;it with CirsdJpinia haliamensis L<a- 

 inarck (if tropical Aniciicii. Tlic existing spe- 

 cies number about two score, and arc found in 

 the Ti'opics of both hemispheres. Ca^sal]>inia 

 is recorded lii'st from the tl]>per Creta(HH»us 

 of the Atlantic Coastal Plain, and it seems 

 prol)able tliat it originated on this continent 

 and n>a(lied Europe dining the Eocene b}'^ way 

 of the iVi'ctic region, since it is common in the 

 OIigocen(\ Miocene, and Pliocene of America. 



Four Wilcox species are referred tt> the form 

 genus Cresalpinites. These species r<"present 

 true forms of Ci^salpinia or of allied genera in 

 this family. One of them ahuost certaiidy 

 belongs in the genus Parkinsonia, a small genus 

 which occurs in the European Oligocene but 

 wliich in the existing flora is conhn<'d to the 

 warmer parts of North America and South 

 .\frica. Fossil forms referred to Ca}sali)iiiites 

 in( hule about 20 from the Em'opean Oligocene 

 and Miocene. 



Tlie genus Gleditsiophj'Uum makes its ap- 

 pearance in the I'pper CVetaceous of the Caro- 

 lina region. It is represented in the Wilcox 

 deposits by S sjX'cies of leaves, leaflets, and 

 pods, which are abundant in many places. 

 Theu" relation to modern genera is uncertain, 

 but they were evidently much like Gleditsia. 



Two genera of Citsalpiniaceaj, HTOiemx-a and 

 Bauhinia, which I confidently expected to find 

 in the Wilcox, must have been present during 

 this time in southeastern North America. 

 Hymcnsea is confined to the American Tropics 

 in the existing flora, where it includ<'s about 8 

 species. It is represented by characteristic 

 forms in the Upper Cretaceous of Alabama. 

 Tlie geims Bauhinia, which contains abotit 1.50 

 existing species of the Tropics of both hemi- 

 spheres has several especially characteristic 

 forms in the IJppin' Ci-etaceous of soutlieastern 

 North America (New Jersey, Marj'laud, and 

 Alabama). 



Tlie family Papilionace^, which comprises 

 more than two-thirds of the existing Legu- 

 minosse, undoubtedly represents the culmina- 

 tion of evolution in the alliance. Most of its 

 species, especially the numerous herbaceous 

 genera, are unquestionably of comparatively 

 recent origin. In spite of this fact, the family 

 is represented by more than 20 species in tlu^ 

 Wilcox. Tliese species are distributed among 

 6 genera, of which Dalbergites, Carpolithus, 

 and Legurainosites are form i^enera and the 



other 8 still exist. Tlie largest genus is So- 

 phora, wliicli inchnh's 7 species, one of which, 

 evideiitly a sti-and ts-])e sinrilar to the cos- 

 mo]>olitan strand plant SopJiora fometilosa 

 Liiuie of tlie existing tropical flora and com- 

 para1)li' in its ludiitat with tliat species, is very 

 alumdant in the Wilcox deposits. Tliere are 

 al)out 2.5 existing speci(>s of slu'ulis and small 

 trees referred to this genus, which are scat- 

 ter<Ml over the wai'mer parts of both hemi- 

 sph<'res and are found <.)n all tropical seashores. 

 About a dozen fossil species ai"e known. In 

 addition to North .America they are f(nuid in 

 both Europe and Asia during the Eocene, a 

 single form from ^Uum Bay (Ypresian) being 

 contemj>oran(H)us with the Wilcox sjiecies and 

 the othei-s being later. Though few species 

 h'av(v been described, the genus is widely dis- 

 tributed in the European Miocen(>, where So- 

 phora (uropxa Unger was a common coastal 

 form of the Mediterranean region throughout 

 the Miocene and into tlie Plioc(>ne epoch. 



Four species, tlu-co based on leaflets and the 

 fourth on a characteristic pod, represent the 

 genus Dalbergia in the Wilcox flora. Two ad- 

 ditional species whose generic relations are not 

 so certain are referred to the genus Dalber- 

 gites. The existing sp(H;ies of Dalbergia num- 

 ber about 80 forms found in the Tropics of both 

 hemispheres, and all show a strong generic sim- 

 ilarity in their foliar characters. More than 

 two score fossil forms arc known. Th(i earliest 

 form occurs in the Atlantic Coastal Plain and 

 western Gre<'nland, so that there is a strong 

 possibflity that the genus was of American ori- 

 gin. If this theory was correct they must have 

 undergone a rapid dissemination, for in the 

 Eocene they are not only found in America and 

 the Arctic region, but also in Europe. The 

 Alum Bay beds of the Isle or Wight (Ypresian), 

 which I regard as contemporaneous, in part at 

 least, with the Wilcox, contain, according to 

 Ettingshausen, 6 species of Dalbergia. Euro- 

 pean deposits furnish about a dozen Oligocene 

 species and a larger number of Miocene species. 

 Dalbergia primseva I'nger, D. rdussrfolia Heer, 

 D. hsenngiana Ettingshausen, and D. hella 

 Heer are widespread coastal forms of the Euro- 

 pean Tertiary. Some of these European species 

 range from tlie late Oligocene tlu-ough the 

 Miocene and into the Pliocene. 



The genus Canavalia is represent(Ml in the 

 Wilcox by a line sjJccies, undoubtcilly the 



