Explanation of the Plates. 



Plate I. 



Figs. 1—5. Priapulus caudatus Lam. forma tnberculato-spinosus Baird. 



Fig. 1. View of the dentary apparatus, the mouth and oesophagus having been opened along 



the dorsal surface. 20 /i. 



A", ventral surface; 1 — 6, the six pentagous of teeth, the teeth of the first one beiiig smallest; a — d, 



different views of teeth, as seen under a magnifying power of about 83 diameters. 

 » 2. Front view of the introvert with the raouth and teeth. u /i. 



V. ventral surface; D, dorsal surface. 

 » 3. Ventral view of the foremost portion of the introvert. 8 /i- 

 » 4. Front view of the introvert with mouth and teeth. i /i. 



V, ventral surface; D, dorsal surface. 

 » 5. Ventral view of the posterior extremity of the trunk with a part of the caudal appen- 



dage adhering. 5 /i. 



The specimens illustrated in figs. 1 — 3 are from Graham Region, those illustrated in figs. 4 — 5 from 



Falkland Islands. 



Figs. 6—11. Priapulus caudatus Lam. 



(Spitzbergen : Trcurenburg bay and Whales point.) 



Fig. 6. View of the dentary apparatus, the mouth and oesophagus having been opened along 



the dorsal surface. 12 /i. 



V, ventral surface; 1 — 7, the seven pentagons of teeth; a — d, different views of teeth from different 



regions of the oesophagus, as seen under a magnifying power of 50 diameters. 

 » 7. Front view of the introvert with mouth and teeth. w /i. 



V, ventral surface; D, dorsal surface. 

 » 8. Ventral view of the foremost portion of the introvert. 8 /i- 

 » 9 — 11. Ventral views of the hindmost part of the trunk of three different individuals, i /i, 



3 /i> 3 A> showing the median ventral space devoid of warts. 



Fig. 12. Priapulus bicaudatus Dan. 



(E. of Greenland: 72° 25' N— 17° 56' W.) 

 Fig. 12. View of the dentary apparatus, the mouth and oesophagus having been opened along 

 the dorsal surface. 12 /i. 



V, ventral surface; 1 — 5, the five pentagous of teeth; a — d, different views of teeth from different 

 regions of the oesophagus. 50 /i- 



K. Sv. Vet. Akad. Handl. Band 47. N:o 1. 5 



