264 



nmscigenus may be recognized by its distinct stripe and dichoto- 

 mous gills, while D. retirugus is sessile or subsessile with branched, 

 reticulate gills. 



Dr. N. L. Britton spoke of the three genera of Cactaceae, Car- 

 negiea, Pachycereus, and Cephalocereiis, and showed specimens of 

 their flowers. The genus Carnegie a, dedicated to Mr. Andrew 

 Carnegie and formerly known as Cereus giganteus, consists of a 

 single species. Some of these plants attain a height of sixty feet 

 and branch at from twelve to twenty feet above the ground. The 

 flowers are funnel-form with a nearly cylindric tube, bearing a 

 few broad triangular scales. Pachycereiis blooms at a different 

 season from Carnegiea and the perianth-tube is clothed with woolly 

 hairs and bristles. 



Cephalocereus which has many representatives in the West 

 Indies and some in Mexico, derives its name from the fact that 

 the top of the plant is hairy. At Key West, Florida, there is 

 a colony of Cephalocereus keyenses which is related to some of 

 the Cuban and Bahaman species. It is the only locality where 

 this species is known to exist. As it is growing here on a Gov- 

 ernment reservation, it will most likely be preserved. 



Mr. Roland M. Harper told of his experiences in the south 

 from July, 1908, to July, 1909. A few weeks were spent at the 

 Biltmore Forest School, North Carolina. Specimens were 

 observed here of Helonias bullata and Dalibarda repens which are 

 not listed in Small's Flora of the Southeastern United States. 

 The former was reported several years ago by F. E. Boynton, 

 while the latter was noticed by Dr. Homer D. House. 



Six weeks were spent in Georgia particularly in the vicinity of 

 Pine Mountains and among the sand-hills of the fall line region, 

 where he found Chamaecyparis thyoides which has not previously 

 been reported from the state. Specimens of Chrysopsis pinifolia, 

 discovered by Elliott in 181 5, and known only from one county, 

 were collected and also a twining Bartonia. Together with, a 

 party of geologists, Mr, Harper made a trip of 260 miles on the 

 Warrior and Tombigbee Rivers in Alabama, which occupied a 

 period of ten days. Here he collected an Egtcisetian which re- 

 sembles E. arvense, but is several hundred miles out of the range 



