﻿40 BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



Hemsley records 7 existing species of Calyptranthes from Central 

 America, two of which occur in Panama. 



Occurrence. — Gatun formation, Gatun Borrow Pits. (Collected 

 by M. I. Goldman.) 



Family MELASTOMATACEAE. 



Genus MELASTOMITES Unger. 



MELASTOMITES MICONIOIDES. new species. 



Plate 18, fig. 2. 



Description. — Leaf oblong-elliptic in outline, of relatively small 

 size, with an equally and bluntly pointed apex and base. Length 

 about 6 cm. Maximum width, in the middle part, about 2.25 cm. 

 Margins entire. Texture subcoriaceous. Petiole short and stout. 

 Midrib stout and prominent. Lateral primaries stout, prominent, 

 diverging from the midrib at an acute angle just above the base 

 and aerodrome. From the disposition of the outwardly directed 

 nervilles from the primaries it is probable that subordinate aero- 

 drome primaries constitute an infra marginal vein on each side, but 

 these can not be made out. Close-set subparallel nervilles run trans- 

 versely between the midrib and the primaries. 



This species is represented by a small amount of fragmentary 

 material, too poor to permit definite generic determination. It is, 

 therefore, referred to the form-genus Malastomites proposed by Un- 

 ger for generically undeterminable leaves of the Melastomataceae. 

 While the fossil somewhat suggests the leaves of various Lauraceous 

 genera, such as CinnamoTnuTn^ Camphoromaea.^ Goeppertia^ and 

 Cryptocarya^ its characters are clearly those of the Melastomataceae. 

 It particularly suggests the genus Tibouchina Aublet, which has up- 

 ward of 200 species of shrubs and undershrubs in tropical America. 



The family Melastomataceae is a relatively large one, with about 

 150 genera and over three thousand species. It is almost strictly 

 tropical, although some members range southward to 40° south lati- 

 tude. This great family is typically American, seven of the fifteen 

 tribes into which it is divided being confined to tropical America, 

 and about 2,500 of the existing species being also endemic in this 

 region. While the geologic history of this vast assemblage of forms 

 is practically unknown, there is no evidence to disprove the theory 

 that it, like the allied families Combretaceae and Myrtaceae, had its 

 origin in that most prolific region — the American tropics. 



The few fossil forms that have been found, including leaves, flow- 

 ers, and calices, have been referred to the form-genus M elastomites 

 first proposed by Unger. A doubtfully determined species, which 

 probably belongs to the Lauraceae, has been recorded from the Up- 



