PLATE XI. 



LAOTIRA CAMBRIA (p. 32). 



Figs. 1,1a. Exumbrella view of a 4-lobed specimen that is fairly regular. The irregularly lobed 



suburnbrella surface, fig. 1«, should be compared with the regularly lobed subumbrella 



surface of fig. 1 of PI. V. The transition between the latter and the former is shown 



by various figures on Pis. IX and X. 

 Figs. S, 2a. Fig. 2 is of the exumbrella surface, in which there are 6 strongly defined lobes and 



several minor lobes. The exumbrella lobes a, b, c, d correspond to the subumbrella 



lobes a, b, c, d of fig. 2a. 

 Fig. 3. Exumbrella view of a large specimen in which are 7 principal lobes and several minor 



lobes. 

 Fig. 4. Subumbrella view of a specimen in which the lobes are inturned very much as in the 



similar forms illustrated by figs. 3 and 4a of PI. VII. 



126 



