470 PROF. E. EAT LANKESTEE ON GOLFINGIA MACINTOSHII. 



In the median dorsal line, at the base of the sclerorhynchus, is placed the triangular anal 

 aperture (a). Symmetrically on each side are the external apertures of the paired nephridia 

 (brown-tubes), fig. 6, dl, dr. The sclerorhynchus is as solid and thick-walled as the 

 scleropyge. Its surface is marked by elongated quadrangular arese differing from the 

 rougher transverse rugce of the scleropyge. The anterior extremity of the sclerorhynchus 

 presents an opening (fig. 7). This is the orifice of invagination of the proboscis or intro- 

 vert, which, when withdrawn, carries with it the tentacular crown and mouth. The form 

 of these parts was made out by dissecting them in their introverted condition (see figs. 9, 

 10, 12). 



The introvert is soft-walled, its outer surface being beset with numerous papillae, and 

 near the mouth with chitinized booklets (as in many Sipunculids). These are shown 

 from different regions of the introvert in figs. 17, 18, 19, 20, and 21. The introvert 

 measured, when extended, two inches and a half in length (fig. 2 d). At its free extre- 

 mity is placed the mouth e, surrounded by a circlet of six symmetrical tentacles. Each 

 tentacle is pinnate, carrying two rows of small processes (about twenty-four in all). A 

 single tentacle is shown in fig. 13 and part of one in fig. 14. 



Internal Features. — The body-cavity (ccelom) is spacious, as in Slpunculus. The 

 characters of the coagulated ccelomic fluid could not be ascertained. 



The long-muscles of the body-wall form a smooth continuous coat, i. e. they are not 

 divided into groups, as in Slpunculus, Phymosoma, and some species of Aspldosiphon. 



The intestinal coils did not extend further than two thirds of the length of the body. 

 This may have been due to the action of the spirit ; but I am inclined to think not. 

 Thus, the posterior third of the body and the scleropyge were simply filled with ccelomic 

 fluid, and contained no "floating" viscera. The intestinal coils were held together and 

 to the body-wall by a delicate mesentery, as in Slpunculus. The position of the retractor 

 muscles of the introvert, and the relations of the brown tubes (nephridia), rectum, 

 oesophagus, and nerve-cord to these and to one another are shown by the drawings of the 

 dissections made (figs. 9, 10). 



There are four retractor-muscles of the introvert, as in Slpunculus (not two only, as in 

 Aspidoslphon). Two of these are attached anteriorly and dorsally (h), and two posteriorly 

 and latero-ventrally (i). 



The anterior pair arise on each side of the rectum, but not quite symmetrically. The 

 posterior pair arise over (and are perforated at their bases by) the nerve-cord, which lies 

 here on the animal's left side near the middle ventral line. 



The anus of Golfingia lies at the base of the sclerorhynchus in the middle dorsal line, 

 and the ventral line corresponding to this is the ventral median line. The nerve-cord 

 does not occupy this middle ventral line, and the only internal structures which exhibit a 

 strict bilateral symmetry in their position are the nephridia (see diagrams, figs. 15, 16, g). 

 The nephridia lie right and left of the symmetrical sclerorhynchus, equally distant on 

 either side from the anus. In the dissection they are seen as shrivelled brown sacs (figs. 

 9 &11). I could not discover their internal openings. In the dissection (fig. 9) the four 

 retractor- muscles are seen attached to the introvert at the point I, and the nerve-cord (ff) 



