136 MADKEPORARIA. 



yS. The stems and prongs diverging in all directions. 



P. Cura(oa 1 (PI. XVII. fig. 3). The branchlets are much bent and expand freely in 

 all directions. 



P. Barbados 2 (PI. XV. fig. 5). A young form forking at very wide angles. 



P. Barbados 3 (PI. IX. fig. 5). The branchlets are stout and somewhat sparse. 



P. Antigua 3 (PI. X. fig. 7). The branchlets are stout, almost nodulated, with 

 irregular forking. 



P. Barbuda 2 (PI. X. fig. 6). Small fragments only. 



P. AnguUla 1 (PI. X. fig. 5). „ . ., 



P. Belize 1 (PI. IX. fig. 1). Stems seem to rise from an overturned tangle. 



P. Florida 5 (PI. XI. fig. 2). The stems are long, crooked, and with sparse forking. 



P. Porto Rico 4. A compact mass of long, wavy, almost serpentine stems ; serpen- 

 tine owing to the succession of their knee-bends, the clustering being so close 

 that prongs are frequently aborted. (Cf. PI. XIV. fig. 1, for a form in the Paris 

 museum, which differs in all details, but shows a somewhat similar growth-form 

 expanding from one initial colony.) 



Doubtful forms. 



P. Barbados 6 (PI. IX. fig. 4). The prongs are aborted into small spur-like pro- 

 cesses, while the stems grow into long tapering points, but the form of the stock 

 is unknown. 



P. Barbados 7 and 8 (PI. IX. figs. 2 and 3). Only known in fragments. 



d. Forms, the initial colony of which rises pear-shaped upon a narrow stalk, with or 

 without a small disk-like base. Upon the division of this swelling colony into two, fresh 

 colonies grow, also swelling, with the result that the stems tend to thicken irregularly as they 

 rise. If the thickening is gradual the stems may remain nearly vertical ; if considerable, then 

 the upper surface of the stock must expand to make room for the swollen tips of the stems. 



P. Cura^oa 2. The stock expands rapidly as a thick cluster rising on a narrow stalk. 



? P. Barbados 4 (PI. IX. fig. 6). A fragment only. 



? P. Barbados 10. A minute pear-shaped stock. ? An initial colony. 



P. Guadalupe 4 (PI. XI. fig. 5). A cluster of thick round-topped stems, radiating 



from a small base. 

 P. St. Thomas 3 (PI. XI. fig. 4). This specimen is so squat that it is more massive 



or columnar than branching. The lobes swell into great rounded masses. 

 P. Porto Rico 3. (See Table I., p. 125, for reference to the original figure.) Stout 



erect stems, gradually thickening, and with well-rounded tops. 

 ? P. Florida 1 (PL XII. fig. 2). See text, p. 71. 



? P. West Indies x. Jf, (PI. XIII. fig. 4). With a tendency to form flabellate clusters. 

 ? P. West Indies x. 6 (PI. XIII. fig. 5). The same, only unique in ending in sharp 



points. 

 P. West Indies x. 8 (PI. XIII. fig. 2). A fragment showing two prongs with flattening 



and dividing tips ; the flattened tips have sharp edges. 

 P. West Indies x. 9 (PL XIV. fig. 2). The tips thicken (? chiefly flatten), expand and 



divide so rapidly and irregularly that the stock grows out laterally over a thin 



stalk. 



