178 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



articulated ; antheridia, carpospores, and tetraspores borne in distinct 

 cavities (conceptacles), which are either external or immersed in the 

 fronds ; antherozoids spherical, attenuated at one end, or provided 

 with two short projections borne on short filaments at the base of the 

 male conceptacles ; carpospores pyriform, terminating short filaments 

 which surround a tuft of parapkyses at the base of the female concep- 

 tacles ; tetraspores zonate, occasionally binate. 



The present order includes all the calcareous Floridece except a comparatively few 

 species which belong to the Kemaliecv, aud Squamariece. Although classed by the 

 earlier writers with the corals rather than plants, the species of Corallincce are now 

 placed at the head of the Floridece, in consequence of their highly differentiated or- 

 gans of fructification. Our knowledge of the fructification of the Corallincce is de- 

 rived principally from the Etudes Phycologiques of Thuret and Bornet and the Re- 

 cherches Anatomiques sur les Melobesi^es of Rosanoff. Thuret and Bornet describe three 

 different forms of conceptacle, containing, respectively, the antheridia, the carpospores, 

 and the tetraspores, the last only being mentioned by Harvey in the Nereis. The 

 tetraspores, which are much more common than the carpospores, are usually zonate, 

 although occasionally binate, and from the fact that they are borne in distinct con- 

 ceptacles, which is not the case with the other Floridece, it had erroneously been con- 

 sidered that the carpospores of the Corallinew were four-parted. The cystocarpic 

 spores, or carpospores, are always pyriform and undivided, and accompanied by para- 

 physes. The number of trichogynes is large, and they project in a tuft at the orifice 

 of the conceptacle at the time of fertilization. The antherozoids differ from those of 

 the other Floridece in having appendages. 



The Corallincce abound in the tropics, and but few representatives are found in 

 northern seas. Our own coast is especially poor in species. The study of the devel- 

 opment of the plants of this order is difficult, owing to the calcareous deposit, and 

 soaking in acid injures the more delicate parts. The species are nearly all fragile 

 when dried, and it is not easy to preserve herbarium specimens in good condition. 

 The suborder may be divided into two tribes. The Corallinece proper have articu- 

 lated fronds, which rise vertically from the substratum, as is seen in our common 

 Coralline. The Melooesiece are not articulated, but form irregular horizontal crusts, 

 which sometimes rise in irregular erect branches. 



Fronds erect, filiform, articulated Corallina. 



Fronds horizontally expanded or vertical and inarticulate. 



Fronds horizontal Melohesia. 



Fronds rising in irregular protuberances from a horizontal base, 



Litliothamnion. 



CORALLINA, Lam.x. 



(From Kopalliov, a coral.) 



Moncecious or dioecious, fronds arising either from a calcareous disk 

 or from interlaced filaments, erect, terete or compressed, articulated, 

 branched, branches opposite, pinnate ; conceptacles terminal, naked or 

 occasionally with two horn-like appendages. 



A genus comprising about thirty to thirty-five species, mostly tropical, C. officinalis, C. 

 squamata, and a few others extending high northward. The fronds of Corallina are 

 formed of a bundle of dichotomous parallel filaments, whose external branches grow 



