1. Detailed study of the digestive system in Henricia reveals that as a result of regional differentiation, particularly involving the lining epithelium, areas specialized for zymogenic and mucous secretion are segregated from other areas adapted for current-production. Secretory areas include the five interradial pouches and vesicles of the cardiac stomach, the pyloric stomach generally but particularly its radial reservoirs, and the median ducts and lateral diverticula of the pyloric caeca. Current-producing areas include the five radial pouches of the cardiac stomach and the gutters leading upward to marginal openings low in the pyloric stomach, and especially the very elaborate Tiedemann's pouches which spring in pairs from these openings and extend along the oral midlines of the pyloric caeca. Other starfishes, such as Asterias, which lack Tiedemann's pouches, restrict their zymogen cells to the lateral diverticula of the caeca and crowd current-producing cells into the median caecal ducts, an area which in Henricia contains an extremely high concentration of zymogen cells.2. Tiedemann's pouches in Henricia are divided into numerous parallel flagellated channels leading diagonally upward into the pyloric caeca. These channels are separated by unique partitions formed by adhesion-seams between opposite side-walls of the pouch. It is evident from their structure and anatomical relationships, and has been experimentally demonstrated, that Tiedemann's pouches are flagellary pumping organs of great effectiveness. They produce currents capable of drawing suspensions or solutions from the stomach and delivering them rapidly along almost the entire length of the pyloric caeca. Centripetal currents stream back into the stomach, and thus a constant circulation of materials can be maintained through the radial secretory and absorptive areas, depending chiefly upon currents generated in the close-set channels of the ten Tiedemann's pouches.3. The customary food and the feeding habits of Henricia are unknown, but several lines of evidence, anatomical and experimental, combine to suggest that this starfish, like at least one other (Porania), may subsist either wholly or in part upon suspended particles gathered by a flagellary-mucous mechanism.4. In Patiria miniata, a species not distantly related to Henricia (same order, different family), Tiedemann's pouches are present and lie in about the same relationship to the pyloric caeca but are fundamentally dissimilar; they lack separate flagellated channels, the side walls being traversed only by parallel stripes of mucous cells alternating with bands of typical cells, and thus are more bag-like in general structure. Although they function similarly to those of Henricia, these much simpler pouches are probably less effective in current production. Asterina gibbosa, closely related to Patiria, has Patiria-type Tiedemann's pouches. Astropecten, in which these pouches were originally described (1816), has relatively small ones of simple construction. Both Patiria and Astropecten have been suspected of supplementing their macrophagous diet by flagellary-mucous particle-feeding, and although their pouches are far less elaborate than those of Henricia they are probably of significance in this connection.5. It is disconcerting to find that Linckia, not at all closely related to Henricia (different order), nevertheless has Tiedemann's pouches and other specializations of the digestive system similar in most respects to those of Henricia. The differences between the pouches in Henricia and Patiria are so fundamental as to suggest that they represent independently evolved solutions to the problem of increasing circulatory efficiency within the digestive tract. In contrast, the pouches of Henricia and Linckia resemble each other so strikingly that it is difficult to conceive of them as having been produced by convergent evolution.6. It is pointed out that detailed studies on many species of starfishes now known only from external anatomy and skeletal features of preserved specimens will provide information upon which to base broader and more meaningful comparative surveys of internal specializations.