310 Transactions. — Botany. 



converse on one side and nearly straight on the other. These 

 cells are sometimes filled with granular matter, which may he 

 forced out by a slight pressure. As the antheridia of the plant 

 have never been observed, it is just possible that these hairs 

 may be antheridial in function. 



Reproduction : Plant dioecious. The conceptacle is sur- 

 mounted by a ring of hairs, and in its interior contains a number 

 of unbranched hairs. The oogonia are obscurely pedicelled, 

 and developed on the cells lining the wall of the cavity. Each 

 oogonium gives rise to a large number of oospheres, thus differ- 

 ing from all other Fucacets that have hitherto been described. 

 Each oosphere is very small, compared with the oospheres of 

 any of the other Fucacece. Fig. 7 shows several oogonia. 



Hab. An annual, common on tidal rocks. 



14. Cystophora. 



I have no remarks to offer upon this genus. 



19. Carpophyllum maschaloearpum. 



In this plant I have noticed antheridia developed from the 

 surface cells of the conceptacles. Mr. F. 0. Bower has noted 

 the same in another genus of Fucacea. 



20. Marginaria boryana; M. urvilleana. 



Hooker's description is {Generic) : " Frond olive-green, uni- 

 laterally, fiabellately pinnate. Leaves, bladders, and receptacles 

 distinct. Leaves sub-confluent with the stem, dichotomously 

 semi-flabellate, vertical. Bladders in series, on the upper mar- 

 gins of the leaves. Beceptacles in series with the bladders, 

 unilateral, sub-simple, terete or compressed, containing spheri- 

 cal conceptacles with obovoid spores." (Sp. boryana :) " Frond 

 many feet long, naked below ; pinna? linear, very long, i - £ 

 inch broad, ribless with hooked serratures. Bladders elliptic- 

 obovoid, as large as a hazel nut, sub-apiculate. Beceptacles 

 cylindric, 1 inch long, acuminate, simple or sparingly spinous. 

 (Sp. urvilleana :) A smaller plant than boryana, but hardly 

 distinct specifically ; the pinnae are a foot long, gradually dilated, 

 simple or fiabellately branched on one side. Bladders smaller, 

 sub-spherical, not apiculate." 



I bave only seen a few specimens of this genus ; but since 

 the two species as figured by Montaigne in the " Voy. au Pole 

 Sud " are evidently male and female plants of a single species, 

 there is probably only one species, subject to a few slight 

 variations. 



The stem consists of three tissues, but presents no pecu- 

 liarities. 



Reproduction : Plant dioecious. I have only seen female 

 conceptacles, which are of the ordinary typical form. It is 



