102 THÉEL, NORTHERN AND ARCTIC INVERTEBRATES. I. STIPUNCULIDS. 
Plate I. 
Figs. 1—5. Phascolosoma vulgare (BLAINV.), from Väderöarne. 
Fig. 1. The animal, natural size. 
a. anus. 
» 2. Hooks of the proboscis. ?49. 
>» 3. The animal opened along the dorsal surface to show the internal structure. 3. 
a. anus. — dr. dorsal retractors, — g. genital bands. — i. intestinal spiral. — m. fixing muscles 
of the intestine. — n. nerve-cord. —- oe. oesophagus. — s. segmental organs. — vr. ventral 
retractors. 
» 4, The foremost portion of the proboscis. 19. 
gi. girdle of hooks. — t. tentacles with the two dorsal sensory pillows. 
» 5. ÅA piece of the body-wall from the transition between the posterior darker part and that 
lying in front of it. 56. 
Figs. 6—8. Phascolosoma eremita (SARS), from Spitzbergen. 
Fig. 6. The animal, natural size. Dredged up at Shoal Point. 
» 7. The foremost portion of the proboscis. NSide-view. 15: Shoal Point. 
» 8. A piece of the body-wall. 36. Horn Sound. 
Figs. 9—13. Phascolosoma elongatum KEFERSTEIN, from the West Coast of Sweden. 
Fig. 9. The foremost portion of the proboscis drawn within itself. 49. Väderöarne. 
br. brain with two pigment-spots. — gi. girdle of hooks. — t. tentacles. 
» 10. Isolated hooks. ?49. Specimen from Gullmarn. 
» 11. The foremost portion of the proboscis with the tentac!es and the circles of hooks. Side- 
view. 29. Gullmarn. 
» 12. The animal. + :Gullmarn. 
» 13. A piece of the body-wall from the transition between the posterior end and that lying 
in front of it. 35. Gullmarn. 
