132 Leodiddce from Fiji and Samoa. 



and appear to be no larger than the others. The tenth parapodium (plate 1, fig. 4) 

 has a prominent setal lobe with its anterior lip asymmetrically bifid and with a rounded 

 posterior lip. There is a single very large black acicula. Dorsally in the seta tuft 

 are a few long, slender, simple setse and ventral to these a dense tuft of compound 

 ones with heavy basal portions and relatively short but stout terminal joints. The 

 dorsal cirrus is Very slender, the ventral one short, carried on the end of a pad-like 

 swelling. I could find no trace of needle aciculse. 



Throughout the anterior region of the body tliis ventral pad-like swelling, which 

 appears at the region of somite 10, is continued and the pads on the two sides of each 

 somite, together with the flattened ventral surface, make up a sole-like ventral region 

 which is in marked contrast to the rounded dorsal region. The pads disappear in the 

 gilled somites, but the flattened ventral surface persists. A gilled parapodium (plate 1 , 

 fig. 3) has a pointed setal region with a single large acicula. The gill is attached to 

 the base of the dorsal cirrus and when fully developed is much larger than the cirrus. 

 As is well known, this species develops at the approach of the breeding-season a 

 posterior epitokous region, and consequently the form of the posterior end depends 

 on the degree of development of the epitokous portion. The swarming occurs in 

 October and November, and my collections were made in April, May, and June, so 

 that the epitokous modifications had appeared only to a limited extent. According 

 to figures given by Friedlander (1898, p. 344) and Woodworth (1907, plate 2, fig. 10), 

 the epitokous portion is much narrower than the atokous, as if a slirinking in diameter 

 occurs at this time. Tliis is contrary to the conditions found in Leodice fucata Ehlers 

 (the Atlantic Palolo, in which a swarming occurs), to L. paloloides Moore, to L. 

 cariboea Grube, and to L. viridis var. vernalis (see page 133), where, when the sex 

 products are formed, the posterior region is much broader than the anterior. Swarming 

 has never been observed in these latter species, but (except for this question of absolute 

 width) the structural modifications are quite as they are in the true Palolo. 



I am indebted to Lieut. Commander R. C. Reed for specmiens of swarming ends 

 collected in Tutuila, Samoa, in November 1920. In these the setse appeared to be 

 longer than in the atokous phase, but careful measurements showed that the absolute 

 length is the same, though because of the narrowing of the body diameter, they extend 

 to a greater distance from the surface. A parapodium from the epitokous region is 

 shown in plate 1, figure 5. The setal lobe is pointed and has a large conical ventral 

 cirrus attached near the end of the lobe. The dorsal cirrus is attached much farther 

 back from the apex, and while conical is much narrower than the ventral one. 



The aciculse are all of one kind, straight and bluntly rounded at the apex. They 

 may be nearly colorless, as happens in the case of the smaller ones, or contain brown 

 pigment, which may be very dense but never appears black. The setse are of two kinds, 

 simple and compound, and are similar in form tliroughout the body. The simple 

 ones (text-fig. 2) are long and sharp-pointed, minutely denticulated along one edge. 

 The compound ones (text-fig. 1) have relatively heavy basal joints which are dentic- 

 ulated at their apices, the terminal joints small, with equal-sized apical and subapical 

 teeth covered by a hood which is minutely serrated along its border. 



The maxillae (plate 1, fig. 6) are dark, with the carrier much hghter than the re- 

 mainder. The two halves of the carrier are closely united throughout most of their 

 extent, the basal ends rounded and relatively broad. The forceps has a heavy basal 

 portion narrowing very abruptly to form the fang at about the middle of the plate. 

 The proximal plates are large, extending back to the carriers; the left one has 3, the 

 right one has 2, indistinctly marked-off teeth. The forceps and proximal plates are 

 very dark in color, with a whitish incrustation along the cutting edges. Distally are 

 2 plates on the right side and 3 on the left. These are very irregular in outline and 

 their apparent form and size depends on the position from which they are viewed, 

 more than Ls the case in the majority of Leodicid maxillie. Their general appearance 

 is shown in figure 6 of plate 1. As compared with the maxilla, the mandible is very 

 large (plate 1, fig. 7) and its lateral margins are much rolled. To the naked eye or under 



