500 FLORA ANTARCTICA. \Fuegia, the 



the capsules of a Nitophyllum : whether they be an abnormal development, or organs of fructification rarely de- 

 veloped in the genus, may be a point of dispute. At first sight they were supposed to be caused by the puncture 

 of an aquatic insect or other animal; but their appearing in specimens from different localities ; their position, con- 

 stantly at the angles of the greater areola?, where four of these meet ; their uniform size ; the constant presence of 

 the cavity filled with elliptic spores, taken especially along with the fact, that there is no sign of disease or lesion 

 in the frond, would indicate these to be organs in a normal condition. 



Plate CXCIV. Fig. II. — 1, Var. a. ; 2, var. /3. ; both of the natural size ; 3, apex of frond ; 4, portion of 

 ditto with conceptacles ; 5, portion of ditto more highly magnified; 6, vertical section of conceptacle ; 7, grumous 

 contents from ditto ; 8, spores from ditto : — all very highly magnified. 



54. ENTEROMORPHA, Link. 



1. Enteromorpha compressa, Grev. Alg. Brit. p. ISO. t. 18. 



Hab. Hermite Island, Cape Horn, Falkland Islands, and Kerguelen's Land ; very abundant. 



2. Enteromorpha intestinalis, Link. Grev. Alg. Brit. p. 179. 



Hab. Hermite Island, Cape Horn ; Falkland Islands, and Kerguelen's Land ; with the former. 



These two species enjoy equally wide ranges with the Ulva latissima. I have found it very difficult to dis- 

 tinguish between this and the former species, even when growing, and between E. compressa and Ulva Lima in a 

 young state. In the Falkland Islands the U. latissima abounds in the land-locked Lagoons, and the IT. Lima in the 

 harbours where no heavy seas run ; whilst the Enteromorpha compressa, and intestinalis, may be collected on the 

 shores of the weather-beaten coasts. Hence it becomes difficult for the collector to regard these species, whose struc- 

 ture and organization are so similar, as anything more than states of one plant, which commences as a pyriform 

 bladder wherever it germinates, but whose future outline is determined by the depth and tranquillity or the reverse 

 of the element it inhabits, and other natural causes. Such specimens as our Herbaria generally afford, are too 

 often, if not fragmentary, immature ; the full development of the species being arrested by the collector, who 

 is content with one entire specimen in whatever stage of growth, and generally preserves it without any note of 

 the conditions under which it was gathered. A few observations on the forms which the Alga assume during dif- 

 ferent stages of their growth, would be eminently useful : portions of a crop of such species as this, which often 

 covers shells or pebbles, might readily be transported to other waters, whose state is very different from what the 

 plant enjoyed before. It cannot be doubted that great changes in form would be the consequence ; and it is on 

 outline alone that specific characters are chiefly founded. 



55. PORPHYRA, Ag. 



1. Porphyra vulgaris, Ag. Grev. Alg. Brit. p. 169. 



Hab. Hermite Island, Cape Horn ; the Falkland Islands, and Kerguelen's Land ; very abundant. 

 This has as wide a range in latitude and longitude as Ulva latissima. 



2. Porphyra laciniata, Ag. Ulva umbilicata, Engl. Bot. t. 2296. 



Hab. Hermite Island, Cape Horn ; the Falkland Islands, and Kerguelen's Land ; very abundant. 



Obviously a variety, or rather state of P. vulgaris ; of which the P. Columbina, Mont., is probably the young, 

 and P. Capensis, Kiitz. another variety. 



56. TRYPOTHALLUS, Hook, fi 'I. et Harv. 

 Frons subcartilagineo-carnosa, vix gelatinosa, undulato-crispata, lobata, e cellulis hyalinis in stratum couglobatis 



