40 

 ON TWO NEW BRITISH MARINE ALGiE. 



BY BEVERLRY R. MORRIS, ESQ., M. D. 



Desmarestia pinnatinervia. 



Iw our November number, we announced on the cover, that Mr. W, Sawers, 

 of Londonderry, had discovered a new Marine Alga, believed to be a Lami- 

 naria. Mr. Sawers communicated specimens to various distinguished Algologists, 

 and also to the late Meeting of the British A.ssociation, but without throwing 

 much light upon it, except in determining that it was new to Britain, Mr. 

 Sawers obtained his '^specimens in August last, after high winds, floating in 

 Lough Foyle, at Moville, county Donegal, in the north of Ireland." Mr, 

 S. not being able to obtain any authority for a previous name to this very 

 interesting plant, called it provisionally, Neuroph/llam Morrisonii, after an 

 intimate friend of his — 'Mr. Charles Morrison. We regret, however, that, at 

 present, this name would seem to fall to the ground; for specimens having 

 been forwarded to our friend the Rev. Dr, Landsborough, he transmitted a 

 specimen to Dr. Montagne, who pronounced it to be Desmarestia pinnaiim.r via. In 

 a letter just received from Dr. Landsborough, he gives the following account 

 of his proceedings in this matter: — 



''In the summer of 1853, a sea-weed was sent to me by Mr. Sawers, which 

 he had found in Lough Foyle, not far from Londonderry. It was unknown 

 to me; neither was it known to some distinguished Algologists, to whom I 

 shewed it. Mr. Sawers, therefore, sent it to be exhibited at the Meeting of 

 the Briti.sh Association at Hull; — but it returned unnamed. 



In the month of September, 1853, he found in the same locality several 

 specimens in better state, and he sent some of them to me. I had been 

 introduced, when I was in Paris, in 1851, to the celebrated Dr. Montagne, 

 Member of the Institute of France, and to him therefore I sent a specimen, 

 and very soon I had the pleasure of receiving a letter from him, saying that he 

 discovered it in 1823, at St. Sebastian, in Spain, and had published a description 

 of it, with a plate, giving it the name of Desmarestia pinna tiner via. He 

 says that it had also been found at Brest, and mentioned by M. M. Crouan, 

 as a variety of Desmarestia Dresnayi, Lam. "Mais je maintiens," adds 

 Dr. Montagne, "la Icgitimitt' de mon espece." 



. It bears some resemblance to a Laminaria, or rather to an Alaria, as it 

 has a midrib. It is an interesting plant, and I congratulate Mr, Sawers on 

 this fine addition to the Marine Flora of Ireland." 



' Mr. Sawers thus describes it: — "Root, a disk; frond, simple; one or more 

 from the same disk — six-twelve inches long, one and a half-two inches broad, 

 with a short stem; colour, olive green. Delicately membranaceous, with a 

 fine midrib, and still finer lateral nervelets opposite. Somewhat resembling 

 delicate fronds of Laminaria phyllitis, with the addition of the midrib, and 

 lateral nervelets." 



