PLATE XXIII. 



LAOTIRA CAMBRIA (p. 32). 



Fig. 1. Transverse section of a 4-lobed individual, cut so as to show the 4 radial canals of the 



exumbrella and the central cavity into which they enter. Attention is called to the 



manner in which the yellow siliceous matter of the matrix is merged into the gray, 



which represents the substance of the lobes of the medusa. 

 Fig. 3. Transverse section of a 4-lobed individual in which the lobes have been replaced by the 



siliceous matter, and nearly all traces of the radial canals obliterated. 

 Fig. 3. A transverse section of an individual with 6 lobes, in one of which the radial canal is cut 



across, and seems to connect with the central cavity. 

 Fig. 4. Central vertical section of a specimen with numerous interradial lobes. Several of these 



are cut across. Very little is shown of the radial canals or central disk. 

 Fig. 5. Transverse section of a specimen with narrow lobes. The section of the radial canals is 



shown in three of them. 

 Fig. 5a. Vertical section of fig. 5 showing the exumbrella lobe and the distorted axial disk. 

 Fig. 6. Transverse section of one-half of a specimen with numerous small lobes in which there 



appears to be traces of a central disk and numerous lobes radiating from it. Several 



sections of the radial canals are shown near the outer margin. 

 Fig. 7. Transverse section of an irregularly lobed individual, showing the arrangement of the 



exumbrella canals. This may be compared with fig. 3a of PI. XVII. 

 Fig. 8. Transverse section of a large irregularly lobed specimen in which the interior canals are 



not preserved. This specimen before cutting was of the general form of figs. 1 and 2a 



of PI. VIII. 

 Fig. 9. Transverse section of a specimen in which nearly all traces of the medusa are lost, with 



the exception of a general outline and the cast of three or four of the radial canals. 

 Fig. 10. Transverse section of one of the compound forms, such as are illustrated by figs. 3 and 4 



of PI. XII and fig. 1 of PI. XIII. 

 Fig. 11. Transverse section of a specimen, such as is represented by fig. 1 of PI. XIII. 

 Fig. 12. Transverse section of a specimen which is of the general type of fig. 5 of PI. XIII. 



150 



