INTRODUCTION TO CRYPTOGAMIC BOTANY. 



179 



coasts. Crouania is remarkable for possessing the habit of 

 Batraehospermum. Halurus and Grijffithsia have their 

 representatives all round our coasts, but are also found in 

 the southern hemisphere, where also a large number of species 

 of Callithamnion occur, though they are more numerous 

 northwards. 



2. Spyridiace^, Harv. {S-pyridiece, J. Ag.) 



Fig. 44. 



a. Conceptacle of Spyridia filamentosa, Harvey, maguified. From a 

 specimen communicated by Mrs. Griffiths,* with the threads in v.'hich 

 the spores are generated from the endochromes. 



h. Transverse section of conceptacle of Chylocladia Kaliformis, Grev. 

 showing the origin of the spores from the central placenta, magnified. 

 From a specimen communicated by M. Lenormand.f 



c. Vertical section of the conceptacle of Gigartina Teedii, magnified. 

 From Sir W, J. Hooker's Herbarium, 



d. Endochromes in the tissue surrounding the conceptacles of Gigar- 

 tina pistillata, to show their communication with each other, highly 

 magnified. From a specimen received from Lenormand. 



e. Portion of conceptacle of Solieria chordalis, after Harvey. 



* The conceptacles are usually lobed, and there are several distinct 

 masses of spores. The simplest case is purposely represented, to show 

 the advance which has been made from the naked nuclei oi CaUithamnion. 



t The walls of the conceptacle appear very different in diflferent 

 sections, according as the section happens to divide the component cells. 

 12 * 



