576 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.50. 



Tertiaries thin but well marked on the underside of the leaf, consist- 

 ing of rather closely spaced percurrent nervilles, which may be all 

 that can be made out if the preservation is not good : these are con- 

 nected by anastomosis, so that their course is usually not straight, 

 the whole forming a relatively open, isodiametric areolation. 



The genus Trigonia, not otherwise known in the fossil state, com- 

 prises about 30 existing species of reclined or climbing shrubs, which 

 are confined to the region between Central America and southern 

 Brazil. 



The Bowen collection contains four specimens from Betijoque and 

 two from near La Salvador a. 



Plesiotype.—C&t. No. 36441, U.S.N.M. 



Order MYRTALES. 

 Family RHIZOPHORACEAE. 



Genus RfflZOPHORA Linnaeus. 



RHIZOPHORA BOWENI, new species. 



Plate 109, fig. 4. 



Stout leaves, elliptical in general outline, abruptly acuminate distad 

 and rounded at the base. The two specimens collected (counter- 

 parts) are conspicuously inequilateral, but this is considered as 

 probably an abnormality. The margins are entire and the texture 

 is coriaceous. Length between seven and eight centimeters. Maxi- 

 mum width about 4.5 cm. Petiole stout, about 7 mm. or 8 mm. in 

 length. Midrib stout, prominent on the under and channeled on the 

 upper side. Secondaries camptodrome, diverging at wide angles, 

 immersed in the leaf substance. The leaf has been galleried by insect 

 larvae and also shows suberized patches such as are commonly seen 

 on the leaves of the existing species. 



The present species agrees with the leaves of the existing Rhizophora 

 mangle Linnaeus in general size, form, and texture; in the thin, open, 

 wide angled, immersed secondaries; in the stout petiole; in the 

 stout midrib, prominent on the lower and channeled on the upper 

 surface; in the decurrent base. It differs in its inequilateral form 

 and acuminate tip. 



There are three existing species of Rhizophora. Rhizophora mangle 

 of the American Tropics is found as far north as Mosquito Inlet and 

 Cedar Key in peninsular Florida. It occurs throughout the Bahamas 

 and Antilles and very generally throughout Central America and 

 northern South America, having in comparatively recent times 



