378 
On Lingulas'!na, Etc .— Ulrich. 
other. Both valves moderately but unequally convex the 
depth of the ventral being less than that of the dorsal and 
greatest about the middle of the shell. Surface With rather 
fine concentric strise and more distant undulations marking 
stages of growth. 
Fig. 1 a. An average specimen of Lingula procteri Ulrich, showing 
the ventral side. The shell is largely exfoliated. Collection of Mr. 
C. Schnchert. 
