176 ALGJE MELANOSPERME.E. [Dictyosiphon. 



coriaceo-membranaceous, linear-obovate, much attenuated at 

 the base. Hook. Br. FL v. ii. p. 27. E. Bot. t. 2136. 



Sea-shores. Wicklow and Killiney, near Dublin. 



2. P. latifolia, Grev. Broad-leaved Punctaria. Frond pale- 

 olive, thick, subgelatinous, tender, oblong, or obovate, suddenly 

 tapering at the base. Hook. Br. FL v. ii. p. 278. Laminaria 

 debilis. Ag. Grev. Crypt, t. 277. (according to authentic spe- 

 cimens.) 



Rare. Belfast ; Dr. Drummond. Kilkea, County of Clare ; W. 

 H. Harvey. This, I greatly fear, is nothing more than a pale variety 

 of the preceding ; both are extremely variable in outline, and, among 

 numerous specimens with which Mrs. Griffiths' kindness has furnished 

 me, I find every gradation of form and colour : some having the dark 

 colour and substance of P. plantaginea with the outline of P. lati- 

 folia ; while others unite the pale colour and delicate substance of 

 P. latifolia, with the narrow outline and tapering base of P. planta- 

 ginea. The same lady informs me that she has found both growing 

 together in the same pool ; a circumstance which seems to confirm the 

 opinion that they are not distinct. But, however this may be, I feel no 

 hesitation in referring Laminaria debilis of authors to this place, 

 having minutely examined Chalmer's original specimens, and having 

 found them to possess a reticulated and truly dictyoteous structure ; 

 in fact, having ascertained that they do not differ in any important par- 

 ticular from Devonshire specimens of P. latifolia. 



14. STRIARIA. Grev. Striaria. 



Frond filiform, tubular, continuous, membranaceous, branched. 

 Root naked and scutate. Fruct. : groups of roundish seeds, 

 forming transverse lines. Grev. Name ; from the striated 

 appearance, caused by the lines of fructification. 



1. S. attenuate, Grev. Attenuated Striaria. Grev. Crypt. 

 Syn. p. 44. Hook. Br. Fl. v. ii. p. 279. Carmichaelia atte- 

 nuata. Grev. Crypt, t. 288. 



Very rare. Belfast Lough ; Dr. Drummond. 3 12 inches high, 

 much branched, a line in diameter ; branches long, irregular, attenuated 

 at base and apex, elegantly marked by the transverse lines of seeds. 

 A beautiful plant, first discovered by Captain Carmichael at Appin, in 

 Scotland, and lately found by Mrs. Griffiths at Torquay, Devonshire ; 

 it may, therefore, be expected in intermediate stations. 



15. DICTYOSIPHON. Grev. Dictyosiphon. 



Frond filiform, tubular, continuous, branched. Root minutely 

 scutate, naked. Fruct. : ovate scattered seeds, lying beneath 

 the epidermis. Grev. Name ; SIKTVOV, a net, and aKfrwv, a 

 tube, from the tubular reticulated frond. 



1. D. fceniculaceus, Grev. Fennel-leaved Dicfyosiphon. 



