536 Cook : A Synopsis of the 



Thrinax praeceps sp. nov. 



Trunk 8-12 cm. in diameter at base, columnar or slightly en- 

 larged upward, seldom attaining over 3 or 4 meters in height 

 The leaf-bases split in the middle of the midrib and long re- 

 main adherent to the trunk. When they finally fall away on older 

 trees a rather rough grayish and longitudinally chinked rimose 

 surface is exposed. 



The stalks of large leaves measure 75-80 cm. in length and 

 1. 2-1. 5 cm. in width. The middle divisions of the leaf are 55 cm. 

 and under in length and attain a width of 4.8 cm., and in the mid- 

 dle of large leaves are united for more than half their length. 

 Cross-veinules numerous, distinct in both surfaces but especially the 

 upper. The white pubescence or tomentum which clothes the young 

 leaves and is especially abundant on the ligule soon disappears, 

 leaving the under side glaucous or slightly pruinose. 



This species is described at some length a little later in a 

 comparison of generic characters under Tkrincoma alta. The type 

 specimen (no. 850) was collected on the precipitous mountain-side 

 which overhangs the road between Utuado and Arecibo, a short 

 distance to the northward from the station where Tkrincoma alta 

 was obtained. 



What is believed to be the same species was collected in a 

 similar situation on the side of a mountain overlooking the town 

 and valley of Lares. 



Thrinax Ponceana sp. nov. Plate 43 



Trunk 5-8 cm. or more in diameter, columnar, or slightly 

 tapering or enlarged upward, 1-4 m. high; surface coarsely and 

 irregularly rimose longitudinally. Leaf-bases separating into 

 abundant rather loose light grayish or brownish fibers. Leaves 

 numerous, large, drooping or pendant; petioles 65 mm. long, 

 1.5-2 cm. wide ; segments attaining 75 cm. in length and 3.5 cm. 

 in width, united for half their length. Seed smooth, mahogany- 

 brown, 5 mm. in diameter. Type specimen no. 1005. 



This species apparently exists in much larger quantities than 

 any other yet known from Puerto Rico, being the predominant 

 plant on several square miles of territory along the range of dry 

 limestone hills which skirt the southern coast of the island, to the 



west of Ponce. Many 



the taller 



shrubs and trefcs wherever there is sufficient soil and water to per 

 mit these to grow and yet not enough to give them exclusive pos 



