(60) 



The present is by no means a rare species on the east coast of 

 Scotland, growing on smooth stones in rock-pools, as well as on rocks 

 near low-water mark. When well grown, and in a good state of pre- 

 servation, it is a beautiful species, and abundantly distinct and easily 

 known from the preceding as from every other British species of 

 Laminaria. There is another plant, however, with which it is often 

 confounded, and under whose name we have often received the present 

 sjDecies, namely, Pundaria plantaginea. From this there cannot be the 

 least difficulty in distinguishing it, when the structure is taken into account, 

 as, when placed under the microscope, the large quadrate cells of Punc- 

 taria may be at once known from the minute cellules on the sm'face of 

 the Laminaria. In old plants too, the fructification and brown colour 

 of Pundaria render it easily recognizable ; but in young specimens these 

 characters are not apparent, young narrow varieties of the Pundaria being 

 almost identical in colour and form with naiTow forms of Laminaria fascia. 



There is perhaps no species of Laminaria more variable in form than the 

 present. We have specimens now before us several inches in length, and 

 scarcely broader than a hair, while in the same patch there are specimens 

 not more than twice the length, but three-quarters of an inch in breadth ; 

 the apex is generally more or less rounded, but frequently retuse or 

 truncate, sometimes obliquely ; the margins all round more or less waved. 

 Sometimes the form is almost linear, sometimes elongate-obcuneate, 

 widening gradually from the base to the apex, and then abruptly 

 truncate. At other times it gradually widens to the middle and then 

 tapers ; sometimes to a rather acute, at other times to a truncate or 

 rounded point. At other times the one side is contracted so that the 

 frond assumes a curved form, whilst in others the frond seems as if it 

 had been nearly cut across, and the wounds all properly healed, the 

 margins being all smooth and even. 



We have met with the plant at all seasons ; but our finest specimens 

 were collected in May, and we are rather inclined to think the plant is a 

 spring species. On one occasion we met with it in considerable abund- 

 ance, covering a smooth stone in a tide-pool near low-water mark. 

 Visiting the same locality in the autumn of the same year, and in the 

 hope of procuring larger and full-grown specimens, we again examined 

 the same stone, but were rather disagreeably disappointed on finding the 

 stone covered with a rich crop of Rhodymenia }xilmata, and not a single 

 frond of our little favourite could be found. 



EXPLANATION OF PLATE CLI. 

 Fig. 1. — Laminaria fascia, natural size. 

 2. — Surface of frond. 

 3. — Section of same. Both magnified. 



