PLATE 9. 
Fig. 1-8. DoapeLia AGASSIZI, sp. nov. 
Fig. 1. Single palatal spine, detached from the epithelium, but still imbedded in the ec 
cuticula of the palatal flap. > 170. Ri 
Fig. 2. Early stage in the formation of a palatal spine. The spine here appears asa _ 
thickened cap on the distal end of the granular basal cell. The thick common cuticula overlies al 
epithelial cells of the figure, but is not here represented. X 175. 
Fig. 3. Base of palatal spine, showing its relation to the basal matrix-cell, and to the 
columnar epithelium. Part of another basal cell is shown at the left, its spine not hanes 
the section. X 175. : 
Fig. 4. A later stage than that shown in the preceding figure, two layers of the young spine 
been formed. X 175. 
Fig. 5. A still later stage of the same, the section passing to one side of the nucleus of the 
matrix-cell. > 175. 
Fig. 6. Later stage of the same process. The spine and basal cell have both increased 
The cytoplasm of the matrix-cell contains numerous irregular vacuoles and is coarsely granular. 
Fig. 7. Section across the long axis of the palatal fold as seen under low magnification; 
surface, forming part of the floor of the pharyngeal duct. The one-layered columnar epithe 
bears a slight cuticula on the dorsal side, a, which thickens greatly on the ventral surface, 6 
contains the palatal spines, differentiated in its substance, and resting upon the ee or 
above it, and projecting freely; c, the free margin of the palatal fold; d, section of a saliva 
xX 18. 
Fig. 8. Detail of fully formed palatal spine showing its relation to the epithelium and to | 
common thick striated cuticula, c, to the surface of which it does not yet extend, being still in 
with its matrix-cell, 6. X 220, 
