ON A NEW SPECIES OF PHYMOSOMA. 179 



DESCRIPTION OF PLATE XII, 



Illustrating Mr. Arthur E. Shipley's paper " On a New Species 

 of Phymosoma, with a Synopsis of the Genus, and some 

 Account of its Geographical Distribution." 



Fig. 1. — A view of Phymosoma Weldonii, enlarged 3 diameters. Tlie 

 introvert with its conical papillae is slightly protruded. 



Fig. 2. — A conical papilla from the introvert, seen from the side and from 

 above. 



Fig. 3. — Some of the depressed oblong papillae from the trunk, enlarged to 

 show the pore and the cuticular plates. 



Fig. 4. — A view of the animal cut open just to the right of the middle 

 ventral line. The introvert is retracted. The ventral nerve-cord is seen 

 running up the introvert and back close to the cut edge ; the right and 

 left retractor muscles and the two kidneys lie on each side of the coiled intes- 

 tine. The kidneys are much elongated, and show irregular swellings. The 

 heart with its diverticula is seen in places. The longitudinal muscles of the 

 body-wall are not indicated. Enlarged 21 diameters. 



Fig. 5. — A diagrammatic view of the head of Phymosoma Weldonii. 

 The collar is completely expanded, and surrounds the head. Part of the outer 

 limb of the lophopbore involving about ten tentacles has been removed in order 

 to show the pigmented area within the lophophore, and the inner circlet of ten- 

 tacles. The lower lip surrounds the mouth, and at its dorsal end fuses with 

 the end of the lophophore. The dorsal side of the tentacles, which are fully 

 expanded, is pigmented. The lophophore is represented too flat; it should 

 be oblique and overhanging the mouth. 



Fig. 6. — A surface view of a piece of the wall of the kidney, showing the 

 glandular areas — crypts — separated from one another by muscle-fibres. 



Fig. 7.— An enlarged view of the end of the coiled intestine, with the heart 

 partially dissected out. The spindle muscle running up the axis of the coil is 

 shown near its termination by the anus. The anterior ends of the kidneys are 

 seen right and left. 



Fig. 8. — A transverse section through the base of the lophophore, showing 

 the lower lip, the mouth, some isolated tentacles, the fused bases of others, 

 and their blood-vessels and nerves. The fusion of the dorsal ends of the 

 lower lip and of the lophophore, and the distribution of the pigmented and 

 ciliated epithelia are seen. 



Fig. 9. — A transverse section through a trunk papilla. This shows some 

 circular muscle-fibres, the ectodermic epithelium passing into the gigantic 



