122 LKODICID^ OF THE WEST INDIAN REGION. 



The prostomium is rounded, almost hemispherical in outline when seen from above. 

 There is one pair of articulated tentacles (plate 9, figure 21) having at least nine articu- 

 lations, and also a pair of slender, tentacle-like palps, longer than the tentacles and not 

 articulated, though their inner surfaces may be much wrinkled. There are two pairs of 

 eyes, of which the ventral pair are the larger, and from a dorsal view are concealed by 

 the bases of the tentacles. The dorsal eyes are small, black, on the median sides of the 

 bases of the tentacles. 



The peristomium (plate 9, figure 21) is a Httle broader than long, with its anterior 

 edge a little narrower than the posterior, and with a thick margin which is recurved 

 behind each tentacle and continued to the ventral surface, where it ends on either side 

 in a thick, posteriorly directed swelling, the two forming an upper lip to the large mouth. 

 Dorsally the anterior margin forms a backwardly directed depression, from the center of 

 which a caruncle-like knob extends forward to nearly the level of the eye. The mouth 

 is large, bounded dorsally by the lobes above mentioned, and ventrally by a prominent 

 lip. Somite 2 is a little wider than the peristomium and about one-half its length 

 (plate 9, figure 21). Succeeding somites widen a little for the first few, but later narrow 

 gradually to the posterior end. 



All the cirri are prominent, the dorsal ones with two joints and needle aciculae, the 

 ventral ones not longer than the parapodium and of uniform diameter, though rounded 

 at the end. There are two pairs of anal cirri, the dorsal pair much the larger (plate 9, 

 figure 23). 



The antero-posterior diameter of all parapodia is about equal to the dorso-ventral. 

 Each has a prominent post- and pre-setal lobe, the two being continuous ventrally, so 

 that the setae appear to arise from the bottom of a deep depression, bounded on three 

 sides by a relatively high wall. The first parapodium (text-figure 442) has rounded 

 anterior and posterior lobes and an inconspicuous ventral one. The dorsal cirrus is 

 twice as long as the setal lobes, its two joints about equal. The ventral cirrus is about 

 as thick as the dorsal and extends to only the end of the setal lobe. There are one or 

 two aciculse in the setal portion. The tenth parapodium (text-figure 443) and one from 

 the posterior end of the body (text-figure 444) are very similar to the first in general 

 form, though they have a distinct ventral lobe on the setal portion which is not present 

 on the first. Their acicular equipment is essentially like the first. 



The setse are relatively long. The compound seta (text-figure 445) has a long basal 

 joint, which widens near its apex and here has a series of denticulations along its convex 

 edge. The terminal joint is relatively long, with an apical and a subapical tooth and a 

 hood. The basal portion of this joint has denticulations along its convex edge. Simple 

 setse are of two kinds, both being found in the dorsal portion of the seta tuft. They differ 

 in size, the larger (text-figure 446) having apical and subapical teeth, covered by a hood, 

 and marginal denticulations. The smaller ones (text-figure 447) are more slender than 

 the others, are denticulated on the margin, and with obscure teeth at the apex. These 

 look as if well-developed teeth had been worn away, but since they occur in this form 

 all through the body I have decided that they are entirely normal. 



The maxilla (text-figure 448) has on either side two rows of black teeth, only the 

 ventral row being figured. The dorsal ones are smaller and would lie directly behind 

 these that are drawn. A slender chitinous rod unites the two sides of each row pos- 

 teriorly. This is smooth at the junction, but toward its end shows indications of separa- 

 tion into minute teeth. There are from 30 to 35 teeth in each row, the largest in the 

 middle, and they gradually become smaller from there toward either end; each tooth 

 (text-figure 449) has a long solid basal portion, the terminal portion bent at an angle 

 with the basal, the whole concavo-convex in form, the figure being drawn from the 

 convex surface. At the apex is a stout tooth, with rows of smaller teeth on either side. 



