174 BRITISH SEA-WEEDS. 



linear conceptacles, which traverse the middle of the frond ; 

 tetraspores in wart-like superficial conceptacles. — Steno- 

 GEAMME, from the Greek stenos, narrow, and gramma, a 

 line. 



The single species composing this genus grows in both 

 hemispheres, though it has never been found in great 

 abundance on any coast. It was first discovered in 

 Spain, in 1823, and has since been dredged in the south 

 of England and in Cork Harbour, but the largest spe- 

 cimens have been brought from California and New 

 Zealand. 



Stenogramme interrupta. The interrupted 

 Stenogramme. 



Trond of a clear pink colour, on a short stem, rising from 

 a disc-root, and rapidly expanding into a fan-shaped mem- 

 brane, varying from three to five inches in breadth ; some 

 specimens are deeply cleft into ribbon-like laciniae, others 

 are less divided, and occasionally throw out oblong or 

 forked leaflets. Spore-conceptacles contained in a nerve 

 running through the centre of the fertile lobes ; tetraspores 

 in dark-red warts, called nemathecia, scattered irregularly 

 over both surfaces of the frond. 



This is one of the most rare of our native sea-weeds, 

 and is the more difficult to obtain as it grows in deep 

 water, and is seldom cast on shore. At first sight the 

 frond appears to be traversed by a midrib, but on closer 

 examination it will be found that the peculiar form and 

 arrangement of the spore-conceptacles give it this ap- 

 pearance, and that barren fronds and those which bear 

 tetraspores are wholly nerveless. I am indebted to Mr. 

 John GatcombCj of Plymouth, for specimens of this 



