l82 



DISCOVERY REPORTS 



Hessle does not call attention to the unusual nature of the gills : they are described 

 by Grube as " foliaceae, quasi lanceolatae " ; and instead of being of the normal cirriform 

 shape they are flattened and leaf-like for about three-fourths of their length, and end 

 in a rounded cirriform tip. The gills (Fig. 75, b) are arranged in two transverse series 

 of three on each side, with the 4th directly in front of the innermost of the series. 



SmiriT 



O 



a 



mTTL 



o-^ 



T-4i 



mm 



O 



T3ram 



O 







Fig. 75. Phyllocomus crocea. 



a. Prostomium. b. Anterior end with gills, c. Posterior member of inner pair of gills on each side. 

 d. Anterior member of inner pair of gills on each side. e. Dorsal bristle. 



Those of the outer pair on each side consist of two membranes, one on each side of a 

 rounded central axis. The posterior member of the inner pair (Fig. 75, c) on each side 

 has, in addition to its two membranes separated by the axis, a second, smaller pair of 

 membranes coming off from the axis and extending for about half its length. The 

 anterior member of the inner pair (Fig. 75, ^) on each side is shorter than the rest and 

 lacks the rounded cirriform tip; it has four membranes, springing from the main axis 



