DE, LAUDEH LINDSAY ON AltTUONIA MELASPERMKLLA. 278 



roundish spermatia (c) Ayhich, however, are sometimes altio rod- 

 shaped*. 



II. ArtJioniapruinosa, Ach,, yar. spilomatica, Fw. (PL VI. fig. 7.) 

 On oaks about Loreh, on the Ehine, Bayrlioffer -, Schcer. Exs, 

 507. The pjcnides are very small, round, black points, having 

 the characters of certain species of the old genus PyrenotJiea {e.g. 

 -P. insculpta, Wallr., P. stictica^ Fr.). The sterigmata («, h) have 

 much the character of those described in specimen No. 2 of -4. 

 astroidea, being simple and linear (J), sometimes branching or 

 spreading below {a), colourless, about *0009 to '00075 inch long. 

 They give off from their apices stylospores (<?), which vary con- 

 siderably in form, size, and colour, and which are generally very 



abundant. Their colour is usually some shade of pale yellow ; 

 their form ellipsoid or oblong, straight or curved ; they are simple 

 or 1-septate, hyaline or granular, about *0003 inch long. 



The ordinary spermogones of the type A. pruinosa (fig. 8) arc 

 generally very abundant, especially on old oaks, in the fissures 

 of the rugged bark, prominent and easily seen when the thallus 

 is pruinose white. The sterigmata are short and simple (a) ; 

 the spermatia in myriads, and more or less ellipsoid or rod-shaped, 

 and simplef (5) . 



This species, however, appears to possess several forms ofsper- 

 mogone and pycnide ; some of which are both abundant, or com- 

 mon, and easily seen, and which have been described by the older 



I^ichenologists as species of Pgrenotliea (P. gregaria, Fw. ; Ze^ 

 * prantTia fuliginosa^ Turn., var. microsticta^ Fw., Tul. Mem. 192; 

 P. stictica^ Fr., Kerb. Syst. Lich. Germaniae, p. 291-5). The 

 spermatia are usually described by authors as oval or ellipsoid. 

 There may be some difierence of opinion as to whether what T 

 have hereinbefore described as j)gcnides and' stgIosj)ores should 

 not be regarded as spermoganes and spermatia. It appears to me 

 that there is a good anatomical distinction (as there may here- 

 after prove to be an equal physiological one) between the cor- 

 puscles which I have described here and elsewhere J as spermatia 



The specimen figured is from Schfiprer's Eis. 16. Section of spcrmogone, 

 greatly magnified, diagrammatic; <r, envelope or perithecium of dark -brown, 

 small, irregular, closely aggregated ceils. 



t The specimen here figured is from Nylander's Eis. [Herbarium Lichcnum 

 Parisiensium, 1854-5] 83. Sterigmata about -00045 incli long; spermatia about 



•00012 long, and -00005 



Arihonia as normally c 

 curved fLich. SrAnd. 2.=> 



spermatia 



Edinb. vol. xxil 



?rmogones and Pycnidos of Lichens ; Trans. Eoy 



