28 BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



a single Australian species, and the North American genus Asimina, 

 with 6 or 7 species being the only conspicuously extratropical forms. 

 The area of maximum representation is southeastern Asia and the ad- 

 joining region of Malaysia, for while only 16 genera are confined to 

 this region it contains over 350 species, and six additional genera 

 (Miliusa, Uvaria, Polyalthia, Oxymitra, Melodorum, and Poporvia) , 

 with a total of over 250 species have the bulk of their species in this 

 area. Only a single genus is confined to Australia, and the bulk of 

 the Australian species are to be regarded as migrants from the pre- 

 ceding area. There are upwards of 100 species and 6 peculiar genera 

 in tropical Africa; and America has about 200 species and 10 peculiar 

 genera. These are all confined to the Tropics, except for a species of 

 Anona, which reaches the coast of peninsular Florida, and for the 

 genus Asimina, with six or seven species of shrubs and small trees of 

 the south Atlantic and Gulf States. One of these, Asimina triloba 

 Dunal, is hardy as far north as New York, and has the distinction 

 of growing the farthest distance from the Equator of any existing 

 member of the family. The fossil record of the Anonaceae is very 

 incomplete, only the genera Anona Linneaus and Asimina Adanson, 

 being known with certainty. Both of these genera are present in 

 the flora of the Wilcox group of the Mississippi embayment. 



The genus Guatteria has not, so far as I know, been heretofore 

 found fossil, except for a doubtful species described by Hollick from 

 the Upper Gretaceous of Marthas Vineyard and Long Island. The 

 genus Uvaria Linnaeus has a Pliocene and three Pleistocene species 

 on the Island of Java, and the genera Melodorum Dunal and Mitre- 

 phora Blume are both represented in the Pleistocene of that island. 



The genus Anona has from fifteen to twenty fossil species, five of 

 which are also represented by seeds. The oldest is a species described 

 from the Dakota sandstone. There is a second species in the late 

 Cretaceous or Early Eocene of the Rocky Mountain province. The 

 flora of the Wilcox affords a glimpse into the true stage of evolution 

 of Tertiary floras in that expanded belt of the American equatorial 

 region which was the center of radiation of so many recent types. 

 There were three exceedingly well-marked species of Anona along- 

 the Wilcox coast and their leaves are very common at some localities, 

 although no seeds have as yet been discovered. I assume that these 

 Wilcox forms had habits similar to those of the majority of the ex- 

 isting species, exemplified by our Florida Anona glabra Linnaeus, 

 or pond apple, which frequents shallow fresh-water swamps, low 

 shady hammocks, or stream borders near the coast. Other species 

 occur in the low coppice association or on edges of brackish swamps 

 on the Bahamas. The cultivated species, as, for example, the Ameri 

 can Anona reticulata, Linnaeus, which is planted in Guam, often 



