106 -: 
I PG: Do 
Fig. 28. 
Fig. 29. 
» SM. 
> Dl 
32 
» 33. 
THÉEL, NORTHERN AND ARCTIC INVERTEBRATES. I. SIPUNCULDS. 
Plate III. 
Figs. 27—28. Phascolosoma procerum MöBivs. Gullmar Fjord. 
20 
A portion of the anterior part of the alimentary canal with vessel and retractors. >P. 
i. intestine. — me. membranes uniting the oesophagus to the retractors. — oe. oesophagus. — 
v. vessel with its branches. — vr. ventral retractors. 
Median section through the foremost part of the proboscis. 1329. 
b. blood in the annular vessel. — br, brain with peripheral cells and central fibrils. — c. cilia. 
cbe. corpuseles of the body-cavity. — ch. chitinous layer. — cm. layer of calcareous substances 
exterior to the cbitin. — f. annular folds, limiting the smooth space behind the tentacles and 
devoid of chitin, — lm. longitudinal muscular layer. — mo. mouth. — nr. nerve-ring. —— n. 
nerve-cord. — oe. oesophagus. — t. tentacles. — tm. transverse muscular layer. — vr. ventral 
retractors. — x. the smooth space behind the tentaeles, devoid of chitin. 
Figs. 29—33. Phascolosoma margaritaceum (M. SaArs). Arctic Sea. 
An animal drawn from the side. Kony Bay in the Sejavin Sound; arctic coast of Asia. + 
a. anus. 
The anterior portion of the proboscis with the tentacles partly cut off. 12. Tromsö. 
A piece of the body-wall from the posterior portion of the body. 39. Locality: 75? n.— 
189 SO Ge / 
gl. flattened oval or, at the posterior extremity of the body, slightly rounded, glandular bodies. 
— p. minute scattered papille. — p. ex. posterior extremity of the body. 
A piece of the skin about 2 centim. in front of the posterior extremity. 36. The same 
animal as Fig. 31. 
A piece of the skin from the posterior extremity of the body. 36. The same animal 
as Fig. 31. 
