The pouch is surrounded by several layers of circular muscles and is lined with a simple, thin, primarily unciliated
, squamous-to-cuboidal epithelium.
Smaller particles of 2.5 microns or less (P[M.sub.2.5]) are considered in the respirable range because they can penetrate even deeper into the lungs, to the unciliated
In contrast with the other parts of the gill filament, the abfrontal surface was unciliated at this stage (Fig.
The abfrontal surfaces were still unciliated at this stage.
According to this classification scheme, sensory structures are found in three general regions of the larval surface: (1) within a band of oligociliated cells called the supracoronal cells that are positioned cells called the supracoronal cells that are positioned aborally to the coronal cells and bordered by the pallial epithelium, (2) between adjacent coronal cells are the intercoronal cells, and (3) within an unciliated
(and often undifferentiated) band of cells called the infracoronal cells that are oral to the coronal cells.
13, 27a) The unciliated ectodermal trunk bent slightly towards the ventral side.
The trunk region of the larvae was unciliated. The trunk gave rise to definitive ectodermal structures, such as cuticle and epidermis.
The circular band or ring of long posterior cilia circumscribing the unciliated
posterior pole beat either intermittently or in a single wave in a counterclockwise direction (as viewed from the posterior of the larva).
At this stage, radioles were simple unciliated
cylinders and bore no pinnules.
rubra by an unciliated
structure she termed the "cephalic mass," implying a specialization for brooding more extreme than is seen in the Chilean oyster.
The gill buds of these young clams are just beginning to form filaments, and subcellular inclusions resembling prokaryotic cells can be identified inside the unciliated
cells located near the base of the filaments [ILLUSTRATION FOR FIGURE 3A OMITTED!.
After the loss of the fertilization membrane upon hatching, the unciliated
portion of the late gastrula enabled it to attach to the substrate, well before the appearance of the brachiolar arms [ILLUSTRATION FOR FIGURE 9F OMITTED].