THE MARINE BOTANIST. 271 



SUMMARY OF THE SPECIES OF THE 

 CALLITHAMNION GENUS. 



Section 1. — Cruciata. Ramuli opposite. 



C plumula. Grows on rocks and algSB near 

 low water-mark, and to the depth of four to fifteen 

 fathom water. Annual. Summer and autumn. 

 Not uncommon. From each joint arises a pair of 

 small opposite ramuli, recurved and pectinated on 

 their inner sides. 



C. cruciatum. Grows on mud-covered rocks near 

 low water-mark. Rare. Abundant on the pier at 

 Torquay. Salcombe. Plymouth. Milford Haven. 

 Cork Harbour. Ferriter's Cove, Kerry. Coast of 

 Down. jS pumilum, Miltown Malbay. Two 

 opposite or four cruciate slender erect pinnated 

 ramuli arise from each joint ; ramuli in very 

 dense tufts at the tips of the branches. /3 ptimilum 

 is a much smaller form, with shorter joints and 

 more dense ramuh. 



C. Jloccosum. Grows on submarine rocks near 

 low water-mark. Annual. Spring-. Very rare. 



