28 LEODICID.E OF THE WEST INDIAN REGION. 



anterior border of the second somite to the middle of the fifth. The nuchal cirri extend to 

 the anterior border of the peristomium. In the first two setigerous somites the ventral 

 cirri are rather prominent, but in those immediately following they are small and 

 attached to the end of a thick pad-like swelling. Posteriorly this pad disappears and 

 the ventral cirrus again becomes prominent. 



The gills occur first on the ninth somite and extend to the posterior end, only a very 

 few of the posterior somites being free from them (plate 2, figure 8). The number of 

 branches seems not to be constant in the first gills, but usually there are several. The 

 tenth somite has 9 branches, and toward the middle of the body there are as many as 

 15. This number decreases at the posterior end, the last one or two having only one 

 branch. 



The first parapodium (text-figure 54) has relatively large cirri and a very small 

 setal lobe, which shows no evident distinction between anterior and posterior lips. 

 A single acicula extends into the setal lobe and two into the dorsal cirrus. The tenth 

 parapodium (text-figure 55) has a very long and slender dorsal cirrus, which retains 

 in alcoholic material a brown patch near the base and bands toward the apex. There 

 is a prominent posterior lip to the setal lobe, its margins being continuous above and 

 below with the anterior. There is a rounded elevation between the two lips and a large 

 acicula protrudes just dorsal to this. A tuft of small aciculse lies at the base of the 

 dorsal cirrus. The ventral cirrus is short and conical, and is carried on the end of a 

 rounded ventral pad. There is a collection of brownish pigment on the dorsal surface 

 of this pad and on the base of the cirrus. The seventy-ninth parapodium (text-figure 56) 

 is very similar to the tenth in general form, but is smaller and the gill is much more 

 prominent. In addition to the aciculse of the types described for the tenth, there is a 

 ventral hooked acicula which appears at about the thirty-fifth parapodium. There is 

 more or less pigment on the cirrus and on the dorsal surface of the setal lobe. 



The one hundred and thirtieth parapodium (text-figure 57) is (in alcohol) a uniform 

 purplish brown except for the white ends of the cirri. The posterior lip of the setal lobe 

 is conical and extends much beyond the anterior. The whole parapodium is much smaller 

 than those farther forward, as is demonstrated by comparing figures 54, 55, 56, and 57, 

 all being drawn to the same scale. 



The setfe are similar in form throughout the body, the difference in length being 

 due to greater or less elongation of the shaft. The simple setse (text-figure 58, showing 

 only a portion) are very long and gently curved with a definite wing along one edge of 

 the curved portion, the opposite edge finely striated and resembling a narrower wing. 

 The compound setse (text-figure 59) are relatively large, the stalks very slightly widened 

 at the end and beveled. Along the longer side are fine denticulations and there are 

 striations on the surface. The terminal joint of each has an apical and a subapical 

 tooth covered by a hood. The pectinate setae (text-figure 60) are much more sharply 

 outlined than is usual in this form of seta, with 9 teeth, the terminal ones equal in size 

 and longer than the others. 



In a posterior parapodium there are two sorts of dorsal aciculse (text-figures 61 and 

 62). One form is more slender than the other and terminates in a very acute point, the 

 axis being a dense black; the other is larger, lighter in color, and curved at the end. 

 Apparently these are similar throughout the body, but I was unable to get many that 

 were entire and can not be certain on this point. As far back as the thirty-fifth somite 

 there is only one of these dorsal aciculse, but behind this point there appear a second 

 dorsal and a ventral one. The ventral aciculse (text-figure 63) are stouter than the dorsal, 

 and each carries a terminal and a subterminal tooth covered with a hood. 



The jaw apparatus is very dark in color. The maxilla (text-figure 64) has very 

 short and almost black carriers, the forceps relatively long and slender and not much 



