76 CONKLIX — EMBRYOLOGY OF A BRACHIOPOD. [April 4, 



Plate IX. 



Figs. 53-55. Three oblique sections from the dorsal anterior (DA) to the ven- 

 tral posterior ( VP) region of a larva of the stage shown in Fig. 31 (the 

 sections are nearly in the plane of the reference line from £ in Fig. 31). 



Figs. 56, 57. Two longitudinal frontal sections of a larva of the same stage as 

 the preceding, Fig. 56 being ventral to Fig. 57. 



Fig. 58. Longitudinal sagittal section of a larva of the same stage as the pre- 

 ceding; the section passes through both the apical and the ventral sense 

 plates (CG and SG). 



Plate X. 



Figs. 59-64. Six transverse sections of a larva of the stage shown in Figs. 

 34-36; Fig. 59 being the most anterior and Fig. 64 the most posterior sec- 

 tion drawn. Fig. 59 passes through the cephalic region ; Fig. 60 lies just 

 behind the anterior mantle furrow ; Figs. 61-64 are through the mantle and 

 peduncle. 



