Dr. Deakin o/i new species of Verrucaria and Sagedia. 33 



with a minute papillated elevation; but as the pore becomes 

 larger and open, this seems to disappear ; frequently in exposed 

 parts of the stone, the outer coat of the thallus falls away, 

 leaving the apothecia much raoi-e prominent and rough, and 

 attached only to the black substratum. Perithecium dimidiate, 

 slightly incurved at the base. Nucleus brown, almost black 

 when dry, in a thin black tunic. Sporidia in asci eight, small, 

 pale, single-celled, ovate-oblong. 



Hab. Limestone rocks, Babbicombe near Torquay, Devonshire. 



The Verrucaria trachona described by Taylor in ' Flora Hiber- 

 nica,' part 2. p. 93, is not, as is shown by Leighton (British 

 Angiocarpous Lichens, p. 50), the V. trachona (Engl. Bot. Suppl.), 

 but an undescribed species; and the V. trachona (Engl. Bot. 

 Suppl.), which he supposes to be Acharius's, and like V. lithina, 

 Tayl., is a Pijrenothea, and named by him P. lithina. Both 

 these species are very different from the above, which is at once 

 distinguished by the black substratum to the thallus ; and the 

 sporidia are ovate, single-celled, and not of a fusiforai shape and 

 four-celled, as is shown in the V. trachona, Tayl., by Leighton. 

 From Pyrenothea lithina they are readily distinguished by the 

 diflference in their generic character. 



V. parva. (Plate I. fig. 2.) 



Thallus crustaceous, thin, ashy-gray, continuous, indetermi- 

 nate, the surface minutely granulated ; apothecia minute, glo- 

 bose, black, prominent ; pore small, at length widely umbilicated ; 

 perithecium entire; nucleus brown, in a pale tunic; sporidia 

 elliptical, two-celled, colourless. 



Thallus thin, crustaceous, of a dull ashy-gray colom*, becoming 

 of a greenish-brown hue when moistened, spreading in conti- 

 nuous indeterminate patches; the surface, when seen with a 

 magnifying power, rough with minute granular-looking points 

 giving it a powdery appearance ; the internal substance white, 

 with green granules thickly scattered amongst it. Apothecia 

 very small, numerous, scattered, full, black, globose, half im- 

 mersed ; pore scarcely visible, at length it is widely open and 

 umbilicated, looking like a minute cup. Perithecium entire. 

 Nucleus brown, in a pale tunic. Sporidia in asci eight, elliptical, 

 two-celled, colourless. 



Hab. Limestone rocks near Torquay, Devonshire. 



This little Verrucaria may have been overlooked as a variety 

 of V. rupestris, but its entire perithecium and two-celled sporidia 

 distinguish it from that species ; and its smaller globose apo- 

 thecia, together with its two-celled sporidia, separate it from 

 V. murina, Leight., which has much larger apothecia, and the 

 sporidia are single-celled. 



Ann.i^ Mag. N. Hist. Ser. 2. Vol.\\\\. 3 



