94 SPH^ROCOCCOIDE^. v. 



Frond originating in a single, oblong or obovate, sinuous or deeply pinnatifid 

 leaf, 4 — 8 inches long and from one to four inches broad, denticulate at the margin, 

 furnished with a strong percurrent midrib, and with opposite, lateral nerves or veins 

 set at an angle with the midrib of about 45°. As the frond grows larger the first 

 formed leaf becomes more deeply laciniated, the laciniaj which were at first little 

 more than denticulations lengthening, widening, and becoming again pinnatifid. 

 The membrane of the older parts decays and the denuded midribs are thickened 

 into filiform, imperfectly winged stems and branches, which bear from their sides 

 and apex numerous leaves resembling the original one. Such specimens are often 

 very bushy and dense. The midribs are usually unbranched, but are sometimes 

 forked. The margin of the frond, which in most cases is merely denticulate, is 

 occasionally bordered with slender, simple or fimbriated laciuulaj, or fringed with 

 great numbers of minute, accessory frondlets. Conceptacles hemispherical, formed 

 from the substance of the midrib or of one of its lateral nerves. Tetraspores in 

 sori generally lodged in minute marginal leaflets, rarely dispersed over the mem- 

 brane in patches following the courses of the lateral nerves. Substance membrana- 

 ceous. Colour a purple lake, turning rather brownish in drying. It does not 

 adhere strongly to paper. 



A specimen from Dr. Durkee has dispersed tetraspores, and unites this species 

 with the D. quercifoUa of the Southern Hemisphere, which Kiitzing nevertheless 

 places in a different genus. 



In deep water the frond often becomes very narrow, with filiform lobes, produced 

 into long tendrils. Some of my Halifax specimens exhibit this character. 



2. Delesseeia fimbriata, Delapyl.; " leaves of the ribbed, oppositely veined frond 

 obovate, pinnatifid; lacinite nerveless or having a vanishing nerve, at length 

 separated as proper, lineai'-oblong, serrated and sinuous leaflets ; soi'i of tetraspores 

 lodged in marginal, acute and acutely toothed fimbrite, sub-geminate ; conceptacles 

 sessile on the parenchyma of the frond." J. Ag. Sp. Alg. 2, p. 690. 



Hab. Newfoundland, De la Pylaie ; fide ./. Agardh. 



Sub-genus 2. Pteridium, Kiitz. Frond alternately or dichotomously branched, rose-red. 



3. Delesseria denticidata, Mont. ; frond alternately decompound or irregularly 

 pinnatifid, costate ; branches linear, the primaiy ones alternate, the secondary often 

 opposite, denticulate or fimbriato-ciliate at the margin ; the lamina penninerved 

 with opposite, oblique veinlets ; sori linear, at each side of the midrib near the ends 

 of the lacinia3. Mont, in An. Sc. Nat. Ser. 3. xii. p. 223. D. alata, var. denticidata, 

 Mont. I. c. xi. p. G2. 



Hab. Shores of Labrador, M. Lamare Piquot, in Herb. Montagne. Brandy Pot 

 Island, River de Loup, Mr. Allom. (v. s. in Herb. T. C. D.) 



