298 SUPPLEMENT. 
Insert at page 187 — 
Chroolepus umbrinum. Kutz. 
Stratum thin, crustaceous, rather pulverulent, reddish brown 
growing pale when dead, threads and branches abbreviated, 
torulose, joints nearly as long as broad, broadly elliptic or sub- 
globose. 
Size, Ce.ls (02 mm. diam. 
Rabh. Alg. Eur. i., 372. 
Protococcus crustaceus, Kutz. Spec. 208. 
Protococcus umbrinus, Kutz. Phyec. Gen., t. 7, f. 2. Cohnin 
Hedwigia i., p. 1. 
On the bark of beech and oak. (Kelvedon. E.G. V.) 
Plate CXXX. fiy.2. Chroolepus umbrinum X 400 diam. 
