BY D. McALPINE. 491 



of scale insects, and so I ha\'e written a shoi't paper upon this 

 particular form. ( Vide Appendix, p. 498.) 



The fungus itself might be directly treated, but the only sure 

 way is to get rid of the cause of the trouble, viz., the insects. 

 The following is the formula recommended for the resin wash: — 



Resin • ... 20 lbs. 



Caustic soda (98%) ... 4^ „ 



Fish oil (crude) ... ... 3 pints 



AVater to make ... ... 15 gallons. 



This is a stock preparation, and when requii'ed for use one part 

 thoroughly stirred is added to nine parts of water. • 



Scientific Descriptiun. 

 Capnodium citrioolum, n.sp. — Citrus Capnodium. 



Forming black soot-like incrustations, peeling off as a thin 

 meml^rane, often covering entire surface of leaf. Colourless or 

 pale green hyphie creeping, copiously branched, septate, up to 

 6-8^ n- broad, intertwining and forming a pavement of cells, 

 giving rise to ascending, short, simple, septate branches, bearing 

 colourless or pale green gonidia, continuous, uni- or bi- septate, 

 spherical, oval or elHptical, slightly constricted, smaller 7i-9| x 4- 

 5^ H, larger 11-24 x 5^-1 1 /z; or in moniliform chains. 



Coloured hyphje greenish-brown to dark brown, closely septate, 

 deeply or slightly constricted, sparingly or copiously branched, 

 rigid, 9i-ll /x broad, bearing similarly coloured gonidia, usually 

 elliptical, uniseptate, 7j-16 x 5i-8i^ fi. 



Perithecia intermixed with spermogonia, antennaria, cerato-. 

 pycnidia and pycnidia, sea-green to sage-green appearing black, 

 oblong to oval or variously shaped, rounded and smooth at free 

 end, with net-like surface, 112-250 x 52-112;/. 



Asci cylindrical-clavate; sub-sessile, apex rounded, 8- 6- or 

 4-spored, 70-80 x 19-20 fx. 



Sporidia brown, oblong, sometimes a little fusoid, generally 

 obtuse at both ends, constricted about the middle, 5-6- septate, 

 often with longitudinal or oblique septa, arranged mostly in two 

 ranks but occasionally in three, averaging 21-24 x 8j-9i fx. 



