CRYSTALLINE STYLE OP LAMELLi BRANCHS 



79 



Fig. 15 Modiolus modiolus; food sorting caecum opened from the dorsal side, 

 along the ridge R'; long arrows indicate course of currents on ridges, short 

 arrows show direction in furrows; R,R' , narrow ridges; T, extension of major 

 typhlosole; T', broad ridge apposing typhlosole in life; mc, mouth of caecum; 

 ig, intestinal groove. 



