DICTYOTA* B v. 



intermediate broken ones, Orev. Alg. "Brit. p. 58. (\\\ us 



PL IV Pig. 36.) 

 •tazonata, I, amour. D. ciliata, Lamour. Zonaria atomaria, 



./ '. Padina atomaria, Montag. P. phasiana, Bory. Stypo- 



podium atomarium, Ktz, Diva atomaria, Woo U. ser- 



rata, Da ( 'mm?. 

 //'/ ; /. On marine rooks, rare. Annual. Bummer. 



In England this species is completely a Bummer plant, 

 reaching Its perfection in July, and decaying before the 

 end of September, at which season ii has losl its glossy 

 surface, rich colours, and much of its delicacy ; it is then 



36, almosl coriaceous, dirty-brown and ragged. 



XIX. DICTYOTA. 



38. dichotoma (The forked Dictyota) j frond regularly dicho- 

 tomous, linear ; segments cuneateat the base, ereel orerecto- 

 patent, gradually narrower towards the apices, axils rounded, 

 I . /. p. 58. (Atlas. PL X. Fig. 37 



Zonaria dichotoma, Ag. Dichophyllium vulgare, Ktz. ]). di- 

 chotomum, Ktz. D. implexum, Ktz. Haliseris dichotoma, 

 Spreng. Diva dichotoma, Huds. Dictyota implexa, /. 

 Hah. Parasitical on various Algse 5 also growing on rockc 



stones in tide-pools near low-water mark, and at a greater 



depth. Annual. Summer. Abundant. 



ery common plant, the mosl widely dispersed of the 



genus to which it belongs, being found along the shores of 



the greater part of the temperate ocean, and also in many 



intertropical Localities. As mighl be expected, it varies 



considerably according to the circumstances under which 



WS, though without any respect to climate, the mosl 



opposite varieties being frequently found on the same 



The variations appear to result merely from the 



depth of water at which the plant grows, and the degree 



of exposure to waves and currents to which it is subjected. 



ik-pools near high-water mark and to half-tide level 



the narrow variety, which sometimes is much narrower 



and greatly more intricate than our figure represe 



the commoner. Near low-water mark in rock-pools, and 



among the Laminaria in sheltered hay-, the broad variety 



occurs, of which the average size is represented in the 



figure. 



\\. STILOPHOB \. 



;*£). rhizodes \-Ukt Stilophora) ; frond Bubsolid, much 



i> 



