GONIADA MACULATA. 465 



The tail is dull greenish on the dorsum and on the feet, and terminates in a 

 moderately tapered region ending in the vent, below which are two cirri of average 

 length — also dull greenish. 



The proboscis (Plate LXIV, fig. 6 a) is elongated and cylindrical, the first or basal 

 region (in extrusion) being minutely and densely papillose. The papillae become fewer 

 in the distal region, and disappear before reaching the ring of large papillae at the tip. 

 When firmly contracted the proboscis is closely striated. The basal region is armed by a 

 row of dark-brown V-shaped denticles on each side (Plate LXIV, figs. 6 a and 6 b), about 

 ten in number in well-developed examples. They diminish in size distally (in extrusion), 

 and also are somewhat less at the proximal end. Slight variation occurs in these teeth. 

 Thus Norwegian examples show the V-shaped teeth with longer limbs and more acute 

 apices, and they are also more closely arranged, though not more numerous. In some 

 British specimens a smaller number may exist on one side, and the last may be irregularly 

 formed or in two pieces. At the end of this region of the organ is a circle of twenty 

 papillae, of a bluntly conical form, and just within them two lateral denticles (Fig. 89) and 

 a few smaller intermediate ones. The larger denticles have a rounded or globular end, 

 connected by a neck with the somewhat palmate distal region which has two large curved 

 teeth (Plate LXIII, fig. 6d), the distal fang of great proportional size, the next smaller, 

 and the succeeding teeth gradually diminishing, the whole number being from six to 

 eight, the British examples presenting a much less globular basal end than that shown 

 by Ehlers. 1 The general outline in Norwegian examples agrees, though the number of 

 processes or teeth may vary. The intermediate small denticles (Plate LXIV, figs. 6 e 

 and 6 c') vary in aspect according to the position, as a rule having a basal end with two 

 flattened lobes or plates, a body terminated by two diverging main fangs, and a smaller 

 lateral fang on each side; but when viewed from the inner surface of the gullet four 

 projecting spikes meet the eye. Three of these occur in a row between the two larger 

 teeth, and on the opposite wall of the organ a pair of small V-shaped denticles are found, 

 and often another near each great denticle. The retractor of the proboscis is very long. 

 The buccal (peristomial) segment is about three times the antero-posterior diameter of 

 the preceding, and increases considerably in transverse diameter. The next segment 

 bears the first foot, which has two somewhat elongated lower lobes with bristles between 

 and above, and superiorly a flattened process continuous with the upper border of the 

 former, and representing the superior lobe or lamella. 



At the tenth foot (Plate LXXV, fig. 12) a single median spine occurs in the conical 

 setigerous region, with a tuft of bristles superiorly and inferiorly, a long median papilla, 

 and a dorsal and a ventral elongated lamella (cirrus) tapered at the tip. The dorsal has 

 a flattened and slightly enlarged tip, a condition due to constriction or sinuosity of the 

 margin. The foot is thus characteristically trificl. 



At the twentieth foot the three lobes and the bristles have a similar arrangement, 

 and so at the thirtieth foot, which, however, is somewhat larger. Between this and the 

 subsequent region a change in the complexity of the foot occurs, often about the forty- 

 first or forty-second. 



1 Op. cit. ; pi. xxiv, fig. 43. 



116 



