108 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



Spores pyriform, on simple or branching stalks from a basal pla- 

 centa 1 13 



11. Wall of the conceptacle thin, composed of the divisions of an in- 



volucre united by jelly Spyridiece. 



Wall of conceptacle thick, sporiferous masses arranged around a 

 placenta Bhodymeniece. 



12. Filaments arising from a single cell at the base of a thin membrana- 



ceous conceptacle which is sunk in the frond. . . Scinaia (Wemaliece). 

 Filaments arising from a distinct basal placenta, conceptacles ex- 

 ternal Spharoeoccoidece. 



13. Fronds coated with a calcareous incrustation Coralltnece. 



Fronds without incrustation Bhodomelece. 



FLORIDE^E INCERTJE SEDIS. 



TEEXTEPOHLIA, (Ag.) Prings. 

 (Named, in honor of Johann Friederich Trentepohl, of Oldenburg.) 



Fronds arising from a cellular base, filamentous, branching, composed 

 of short cells placed end to end, branches ending in a hair; spores single, 

 borne in oval cells terminating lateral branches ; antheridia and tetra- 

 spores unknown. 



A genus which in the present paper comprises a number of small marine species 

 placed by some writers in Callithamnion and by others in Chantransla. In the Nereis 

 Am. Bor., Harvey placed T. Dariesii and T. rirgatula in Callithamnion. But cystocarps 

 and antheridia are wanting, and according to Thuret and Bornet, Areschong, and 

 Pringsheim, the spores are undivided, although, on the other hand, Agardh and Harvey 

 state that they are tripartite tetraspores. We have never seen any indication of divis- 

 ion in American specimens. The genus Chantransia as limited by Thuret included not 

 only marine species, but a number of fresh- water forms. Sirodot, however, in his Fttide 

 stir la Famille des L6man6acees, Auuales des Sciences, 5th Series, Vol. XVI, has shown 

 that at least some of the fresh- water species of Chantransia are nothing but the initial 

 stage of different species of Lemanece. On the other hand, Chantransia investiens, Lenor., 

 a luinute fresh-water alga which grows on different species of Batrachospermum, and 

 which is made the type of the genus Balbiania by Sirodot, has distinct antheridia, 

 trichogynes, and cystocarps, and this is also the case with tho marine species C. corym- 

 liifera described by Bornet and Thuret in Notes Algologiques. The species of Chantransia, 

 then, may be divided into two sets. In the first, including C. investiens of'fresh water 

 and the marine C. corymbifera, we have autonomous species related to Callithamnion, 

 and differing in the simpler procarp and cystocarp and in the undivided non-sexual 

 spores. In the second set we have the numerous fresh-water Chantransia;, in which 

 there are no cystocarps, in which the species are not autonomous, but merely prothalloid 

 stages of other species. 



The question remains as to the relations of the marine Chantransia; in which no 

 cystocarps nor antheridia have been found. Judging from analogy, if they are 

 initial stages of other plants, those plants must be members of the NemaUece. But 

 the habitat seems to forbid such an assumption, since the marine Chantransice abound 

 on Zostera, lihodymenia, and other alga3 on which certainly no species of Nemalion or 

 other related genera occur on our coast. We have thought best, in the absence of 

 direct information with regard to cystocarps and antheridia in the species here included, 



