CONTRIBUTIONS TO BOTANY. 
243 
its four angles, at first into two and afterwards into four equal 
achenia, angular within, flattisli on the dorsal face, and some- 
what winged on the margins, the dorsal side being thick and 
of a remarkable spongioid texture, composed of numerous very 
long narrow cells, which radiate towards the periphery, all 
covered by a reticulated membrane. A slender central column 
is found in the axis, which splits to the base into two parts 
that again subdivide, forming fom’ equal, erect, rigid, aristi- 
form supports, which are suddenly reflected at the summit 
into as many rigid funicular chords, whence the achenia are 
.suspended at a point near their base. It is requisite that the 
fruit should dry in the open air to exhibit this structure com- 
pletely. Upon the branch, after the fall of the leaves, the 
panicle remains, the pericarp dries and falls off, the carpels 
separate and are seen hanging from their spreading funicular 
supports ; and when at length the achenia drop off, the divided 
column remains, supported by the persistent unequally rup- 
tured calyx. In the ventral angle of each achenium is an 
indehiscent, somewhat osseous cell, of half its length, of an 
oblong shape ; and upon one of its sides there is a longitudinal 
narrow channel, filled with soft matter and nutrient vessels 
which penetrate into the cell below its apex, and to which the 
single terete seed is attached in a manner similar to that de- 
scribed in Rhabdia. The lateral large open foramen leading 
into a pseudo-cell, a characteristic feature 'vcvBourreria^ is alto- 
gether wanting in Crematomia — a circumstance that affords a 
ready distinction between the two genera, which otherwise 
much resemble one another. This structure of the flower, 
ovary, and fruit renders Crematomia a valid genus of the 
Ehretiacece. The achenia, with their pericarpial covering, are 
well depicted in Richard’s drawing of a Cuban plant. 
All the known species of Bourreria are confined within the 
limit of the West-India Islands ; several belonging to Grema- 
tomia have a similar origin ; but one-half of its known species 
extend into the Columbian portion of the continent and into 
Mexico. 
Crematomia, gen. nov. — Calyx tubulosus, ad medium in 
dentes 5 acutos divisibilis, dentibus intus pilosulis, mar- 
ginibus dense tomentosis, sestivatione valvatis, primum 
firme adliaerentibus, demum segregatis, aut siepe in lobis 2-3 
imequalibus constans, persistens. Corolla tubulosa, carno- 
sula, tuho calyce longiore, fauce paulo ampliore, limbo 
5-partlto, laciniis orbicularibus vel ovalibus, imo brevissime 
unguiculatis et rotundatim cordato-auricidatis, patentibus, 
sestivatione quincuncialiter imbricatis. Stamina 5 (rarius 6), 
