. Bulletin of the Museum of Comparative Zoology at Harvard College. Zoology. 18 bulletin: museum of comparative zoology walls. These constitute the so-called submuscular glands, and dis- charge their secretions directly through the overlying muscular layers to the surface of the body. The submuscular glands are usually limited to the head region of the body (Text-fig. 19), but in some instances extend backward throughout nearly the whole length of the esophageal region, as in Amphiporus nehii- losus (Text-fig. 3), or quite to the intestinal region, as in Emplectonema hilrgeri. As is the case w
. Bulletin of the Museum of Comparative Zoology at Harvard College. Zoology. 18 bulletin: museum of comparative zoology walls. These constitute the so-called submuscular glands, and dis- charge their secretions directly through the overlying muscular layers to the surface of the body. The submuscular glands are usually limited to the head region of the body (Text-fig. 19), but in some instances extend backward throughout nearly the whole length of the esophageal region, as in Amphiporus nehii- losus (Text-fig. 3), or quite to the intestinal region, as in Emplectonema hilrgeri. As is the case with the true cephalic glands, the submuscular glands are compound, each consisting of a number of gland cells hav- ing a common duct leading to the exterior (PI. 20, fig. 123). Caudal Cirrus. In addition to the pair of peculiar cirri which Verrill ('92) has described for Nectonemertes, and which are situated immediately behind the head, the only appendage found on the body of any ne- mertean is the caudal cirrus, or caudicle. This appendage is found only in the genera Valencinura, Zygeupolia, Mi- CRELLA, MiCRURA, Cerebratulus, and DiPLOPLEURA, all belonging to the Hetero- nemertea. It represents a slender prolon- gation of the body beyond the opening of the alimentary canal. This organ has been very fully studied in Zygeupolia by Miss Thomjtson (:02), who finds it to be pro- vided with both circular and longitudinal muscles more or less continuous with the two inner muscular layers of the rest of the body, with slender prolongations of the lateral nerves (Text-fig. 4), and with a lai-ge central blood space connecting both with the dorsal and with the latei-al blood vessels of the body. The outer longitudinal musculature, cutis, rhynchocoel, alimentary canal, and sexual organs are wholly Fig. '^.—Zygeupolia littoralis Diagram of posterior end of body, sliowing caudal cirrus with large central blood lacuna (bl); hi, lat- eral nerve, extending into caudal cirrus {In');
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectzoology, bookyear1905
