EXOGONE GEMMIFERA. 151 



making a second new genus (Syllia) for it. 1 The example from Weymouth secreted a 

 tube fixed to the glass, and was procured amongst sea- weeds. It may be a male bud 

 of Exogone gemmifera. 



2. Exogone gemmifera, Pagenstecher, 1863. Plate LIX, figs. 5 and 6. 



Specific Characters. — Head with fused palpi forming an even rim. Tentacles clavate. 

 Eyes four, with lenses, connate on each side, the anterior the larger. Body about 3 mm. 

 long, with 30 — 32 segments, yellowish or pinkish, bearing embryos along the dorsal or 

 the ventral surface. Tail terminating in two slender cirri. 



Synonyms. 



1863. Exogone gemmifera, Pagenstecher. Zeitsch. f . w. ZooL, Bd. xii, p. 267, Taf. xxv and Taf. xxvi, 



f. 1, 2, 6, 7, 8. 



1874. „ naidina, Mcintosh. Ann. Nat. Hist., ser. 4, vol. xiv, p. 198. 



1875. „ „ idem. Invert, and Fishes St. Andrews, p. 121. 



1884. „ gemmifera, Yiguier. Arch. Zool. Exper., II, p. 69, pis. hi and iv, f. 21 — 37. 

 1890. „ „ G-iard. Bull. So. Fr. Belg., t. xxii, p. 78. 



Habitat. — Under a stone near low water-mark, East Pocks, St. Andrews (E. M.), 



1864. Lochmaddy, North Uist, between tide-marks. 



Between tide-marks at Cette, Coast of France (Pagenstecher) ; Bay of Algiers 

 (Viguier). 2 



The Head has anteriorly a rounded border of the fused palps with a slight median 

 notch. On the ventral surface a median groove indicates the palps more clearly. The 

 cephalic region proper bears two brownish-red eyes on each side, the anterior the larger, 

 and all furnished with lenses. A median and lateral tentacles are situated in front of the 

 eyes. They are short, enlarged at the base, and the lateral are rather blunt distally, 

 whilst the median is the longer. The tips of these have palpocils. The cephalic segment 

 is closely united with the buccal, but, as Viguier points out, they are distinguished by a 

 line behind the eyes. 



Body translucent, rather less than one eighth of an inch in length, slender, very 

 slightly tapered anteriorly, but more distinctly so posteriorly, where it terminates in two 

 slender cirri on each side of the anus, and Pagenstecher found refractive corpuscles near 

 the bases of these cirri. The first segment has only a small cirrus and is separated by an 

 undulating line from the buccal (Claparede and Viguier). A minute ciliated groove (sense 

 organ ?) occurs immediately in front of the cirrus (Viguier). The second bristled segment 

 is peculiar in having no dorsal cirrus. 



The proboscis has a single tooth anteriorly (Plate LIX, fig. 6), and Viguier indicates 

 a break in the pigment about its middle. The proventriculus is situated opposite the 



1 Aimel., II, p. 80. 



2 It is interesting to find that this observer obtained his specimens by following a very old plan 

 at St. Andrews — viz. by removing portions of rocks, stones, or calcareous algas at low water and placing 

 them in vessels of sea-water, when the minute annelids hy-and-by leave the shelter of zoophytes, 

 sea-weeds, or crevices, and appear at the water-line of the vessel. 



