LICHENES BRITANNICI EXSICCATI. 83 



No. 



85. Lecidea mfestnla. J^i/l. 



86. Lecidea luteola. Ack. 



87. Lecidea fusco-lutea. (Dcks.) 



88. Lecidea latypodes. Ni/l. 



89. Lecidea sympliorella. ■N'yl. 



90. Lecidea limosa. Ach. 



91. Lecidea lugiibris, (Smmrf.) 



92. Lecidea coracina. (Ach.) ^ 



93. Lecidea Caradocensis. Leight. 



94. Lecidea sanguinaria. (Z/.) 



95. Lecidea urceolata. Ach. 



96. Xylographa parallela. {Ach.) 



97. Xylographa laricicola. Nyl. 



98. Opegrapha lentiginosa. Lyell: 



99. Arthoiiia varians. Nyl. 

 100. Endocarpon miniatum. (L.) 



We understand that the few copies of the above, published by 

 the Author, are intended exclusively for public herbaria. 



Reproductiok of Desmids. — Professor Leidy, at a late meeting 

 of the Academy of Natural Sciences of Philadelphia, made some 

 remarks on the mode of reproduction and growth of the Desmids. 

 In illustration, he described a common species of Docidium, or 

 Pleiu-otenmm. This consists of a long cylindroid cell, constricted 

 at the middle, and slightly expanded each side of the constriction. 

 When the plant is about to duplicate itself the cell- wall divides 

 transversely at the constriction. From the open end of each half 

 shell there protrudes a colourless mass of protoplasm defined by 

 the primordial utricle. The protrusions of the h«lf cells adhere 

 together, and continue to grow. The bands of endochrome now 

 extend into the protrusions, and subsecjuently keep pace with their 

 growth. The protrusions continue to grow until they acquire the 

 length and form of the half cells from which they started. The 

 exterior of the new half cells thus produced hardens, or becomes a 

 cell wall like that of the parent half cells, Li this condition two 

 individuals of Docidium are frequently observed before separation. 

 During the growth of the new half cells the circulation of granules 

 in the colourless protoplasm is quite active. In a species of 

 Docidium 1-5 m.m. long, by 1 m.ra. broad, the growth of the new 

 half cells was observed to be at the rate of about -35 m.m. in an 

 hour. — American Naturalist. 



Epickisis Hymenomycetum. — We are permitted to state that 

 the Rev. M. J. Berkeley is engaged in the preparation of a work 

 which will supiDlement the " Epicrisis " of Fries, and include all 

 extra-European Hymenomycetes. Thus, the work of the venerable 

 Swedish, mycologist will be rendered complete. 



