Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum . asciculated. Setae. Setae minute, golden-yellow, about 3 mm away from anterior end oftrunk. When dissected out and viewed under compound microscope, each setaconsists of a straight shaft with a curved terminal end (Fig. 17B). Proximal half ofshaft broader with a few concentric markings at base. Interbasal muscle absent. Internal anatomy Alimentary canal. Alimentary canal comparatively short, about three timestrunk length and with relatively few coils (Fig. 18). Intestine attached to body ECHIURA FROM SOUTHERN AFRICA 6
Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum . asciculated. Setae. Setae minute, golden-yellow, about 3 mm away from anterior end oftrunk. When dissected out and viewed under compound microscope, each setaconsists of a straight shaft with a curved terminal end (Fig. 17B). Proximal half ofshaft broader with a few concentric markings at base. Interbasal muscle absent. Internal anatomy Alimentary canal. Alimentary canal comparatively short, about three timestrunk length and with relatively few coils (Fig. 18). Intestine attached to body ECHIURA FROM SOUTHERN AFRICA 63 wall by a few thin mesenteric strands. Foregut is a narrow tube, about 4 mm long,ending at ring sinus. Presiphonal region of intestine 6 mm in length, marked bypresence of a ciliated groove. Ciliated groove commences soon after ring sinusand leads into intestinal siphon. Siphonal region of intestine considerably dilatedand extremely thin-walled. Intestine narrows in postsiphonal region and leadsinto more or less straight rectum. A small, spherical rectal caecum s pint r a v Fig. 18. Ochetostoma palense. Dorsal dissection of the trunk,showing the alimentary canal. Anal vesicles. Anal vesicles (Fig. 18) small, less than one-quarter trunklength. Ciliated funnels minute, unstalked, on surface of both vesicles. Gonoducts. Gonoducts three pairs, spherical to somewhat oval in shape withweakly coiled gonostomal iips (Fig. 19A). First pair of gonoducts lips broad, unlike condition in several other species of and third pairs of gonoducts much larger than first pair. 64 ANNALS OF THE SOUTH AFRICAN MUSEUM
Size: 1298px × 1926px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, booksubjectnaturalhistory, booky
