2<i THÉEL, NORTHERN AND ARCTIO INVERTERRATES. TI. PRTAPULIDS, ECHIURIDS ETC. 



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Plate I. 



Figs. 1 — 2. Priapulus caudatus Lam. 



B. 



Fig. I. Posterior part of the body with the caudal appendages. Dorsal view. J , ! 

 » 2. A vesicle of the appendage. f. 



Figs. 3 — 6. Priapnlus bicaudatus Danielssen from East Greenland. 



Fig. 3. Ventral view of the animal. f. 

 gp. genital pores. 

 Posterior part of the body. Dorsal view. f. 



Processes or papillffi forrning rings near to the posterior extremity of the trunk. f. 

 A vesicle of the caudal appendages. f. 



Figs. 7 — 8. Echiurus Pallasii Guérin Meneviixe, from Väderöarne. 



Fig. 7. The animal having the proboscis broken away. Ventral view. -|. 

 » 8. The animal opened to show the internal structure. 



aa. cloacal appendages or pöuches. — ai. accessory intestine. — bli. basal parts of the hooks or 

 sct;e. — br. bristles. — clb. dorsal vessel. — t', tunnel shaped opening of the segmental organs or 

 uterine pouches. — i. intestine presenting its circumvolutions. — Ju. junction between the two 

 vessels. — m. muscles. — mc. muscular commissure. — ms. mesenterial slit. — nb. nervous cord 

 and vessel. — oe. oesophagus. — ph. phaiynx. — r. rectal portion of the intestine. — s. seg- 

 mental organs or uterine pouches. 





