12 LEODICID^ OF THE WEST INDIAN REGION. 



prostomial lobes are imcolored, but there is a colored area between the lobes on the 

 ventral surface. 



The tentacles (plate 1, figure 2) are long, the median unpaired extending as far as 

 the eighth somite. The inner paired are rather more than three-quarters as long as the 

 unpaired, the outer paired about half as long as the median. All of the tentacles are 

 jointed, becoming moniliform toward the tip, their ground-color pure white, but with 

 brown or purple bands at all constrictions. There is one pair of black eyes, situated at 

 the bases of the inner paired tentacles. 



The peristomium (plate 1, figure 2) is longer than the prostomium, with a narrow 

 dorsal collar extending over the base of the latter. The anterior edge of this collar is 

 colored, but, as is shown only if it is extended, its posterior edge is colorless. The surface 

 of the peristomium is colored much like that of the prostomium, with a light-brown 

 pigment, and is iridescent. The second somite is colorless, and later somites are brown 

 with larger or smaller white areas. In the specimen figured, somite 5 had only a very 

 narrow anterior colorless band, somites 2 and 9 were entirely uncolored, and somite 10 

 had only a very faint trace of pigment along its anterior border. These color arrange- 

 ments are continued to the posterior end, except where modified by the presence of 

 sex products. There is a noticeable brown band at the base of each parapodium, and 

 the ventral surface is colored much like the dorsal except that the tint is fainter and 

 there is more iridescence. The nuchal cirri are long, reaching the middle of the pro- 

 stomium (plate 1, figure 1); these are foreshortened in figure 2. The dorsal cirri (text- 

 figures 3, 4, 5, 6) are relatively long, all colorless, but banded with brown or purple. 

 These bands occur at constricted parts of the cirrus, but there is no true articulation. 

 The anal cirri (plate 1, figure 4) are two pairs, both ventral to the anus, the dorsalmost 

 the larger and colored, the ventral ones being uncolored. 



A sexually mature female showed the entire sex region of a sage-green color, due to 

 the contained eggs, the only trace of the original coloration being a narrow brown band 

 along the anterior border of each somite, and a faint shading over the dorsal surface. 

 In alcoholic material a good deal of the brown coloration about the head and the brown 

 band on the anterior margin of each somite persists. 



The gills appear on the fifth somite as a one-branched structure which becomes two- 

 branched on the sixth, six-branched on the seventh, eight-branched on the tenth, nine- 

 branched on the fifteenth, and fifteen or more branched in later somites. The number of 

 branches begins to decrease from the thirty-fifth to the fortieth, becoming three-branched 

 by the forty-fifth, and gills disappear entirely at about the fifty-eighth. At their greatest 

 development the gills are very prominent, meeting over the dorsal surface of the body. 



The first parapodium (text-figure 3) has a very long dorsal cirrus, banded with 

 brown, but not definitely articulated. The ventral cirrus is not more than one-quarter 

 as long as the dorsal and is short and thick. The setal lobe is very small, its posterior 

 lip being a trifle longer than the anterior. In the figure drawn (a posterior view) the 

 anterior lip is obscured by the posterior. There are aciculse in the setal lobe and needle 

 aciculsB extending into the base of the dorsal cirrus. 



The tenth parapodium (text-figure 4) has a much larger setal lobe than the first, 

 but the arrangement of anterior and posterior lips and aciculse is much the same. Its 

 dorsal cirrus is long and slender, extending beyond the tips of the slender gill-filaments, 

 which in this somite are eight in number. Inside the body-wall is a dense black patch 

 of pigment just internal to the base of the dorsal cirrus. The ventral cirrus has a much 

 swollen base, from the end of which the cirrus proper arises. This pigment patch and 

 the peculiar form of the ventral cirrus are characteristic of most of the parapodia of the 

 anterior region of the body. 



