Squamariaeece 



43 



Order II. CRYPTO NEMIACE^E. 



The fertilized carpogonium sends out a long, branched ooblas- 

 tema-filament, the terminal cells of each branch conjugating with 

 an auxiliary cell. From the latter the gonimoblasts arise. 



Family 1. SQUAMARIACECE. 



This family consists of a small group of marine, or rarely fresh- 

 water Algae, which are minute, flat, gelatinous or membranous 

 expansions, commonly encrusting stones, 

 shells, or larger Algae. The thallus usually 

 consists of dense, vertically arranged cell- 

 filaments. Tetrasporangia are formed in 

 various ways, and often give the surface of 

 the thallus quite a verruculate appearance. 

 The sexual organs are developed in cavities 

 or ' conceptacles ' in the upper surface of the 

 thallus. After the fertilization of the carpo- 

 gonia these ' conceptacles ' contain numerous 

 cystocarps. 



Genus Hildenbrandtia Nardo, 1845. 

 This genus consists of a crustaceous expanded 

 thallus, of a blood-red, dark red, rose, or 

 brown colour, firmly adhering to rocks and 

 stones on the sea-shore or in rivers and 

 streams. The thallus is composed of compact, vertically arranged 

 cell-filaments, with subcubical or oblong cells. The cell- walls are 

 colourless and strong. 



There is only one British freshwater species H. rivularis (Liebm.) J. Ag. 

 (fig. 4) which occurs as dark red patches on rocks and stones in streams and 

 dripping places. 



Fig. 4. Hildenbrandt- 

 ia rivtilaris (Liebm.) J. 

 Ag., from Shipley Glen, 

 W. Yorks. A, section 

 of thallus. B, surface 

 view (x400). C, two 

 cells showing the chro- 

 matophores ( x 800). 



