80 



LEODICID.E OF THE WEST INDIAN REGION. 



similar setae lies just posterior to the anterior dorsal lobe. Two large aciculse lie in the 

 setal portion, and a tuft of needle acicula? extends into the dorsal cirrus. This form of 

 parapodium is retained for a number of somites, but toward the middle of the body 

 the ventral pad becomes shorter and the whole parapodium becomes conical in form, 

 the end of the posterior lobe being the apex of the cone. The dorsal cirrus becomes 

 very long and slender. Toward the posterior end the parapodia are longer and protrude 

 to a greater distance from the body than anteriorly, but the form is essentially as before, 

 as is the acicular arrangement. The dorsal cirrus is very slender, being larger than the 

 gills in the region where the latter has only one filament. 



The setse of the first parapodium (text-figure 281) are very characteristic, being 

 large and slender and of a glassy appearance. At the apex is a large terminal and a 

 smaller subterminal tooth, the whole covered with a hood, which has a peculiar thick- 

 ening at its apex. At a relatively considerable distance from the apex is a deep- inden- 

 tation on one side, which does not divide it entirely into basal and terminal joints. 

 In the tenth somite the setse of the vertical row are rather short, extending only a short 

 distance from the surface of the setal lobe. Each (text-figure 282) has a stout stalk, 

 tapering to an acute point, with narrow wings, only one being shown in the figure. 

 The setse of the dorsal tuft are larger than these, but do not differ essentially from them 

 in form; among these are pectinate setse (text-figure 283) with 20 or more short teeth. 

 Toward the middle of the body the pectinate setae make up most of the seta-tuft, though 

 a few simple ones also occur. They all have much longer stems than anteriorly, extend- 

 ing to a considerable distance from the surface. 



The gills begin with a one-branched form which arises on the seventh somite. On 

 the next somite the number of filaments is 2, on the twelfth and later it is 3 or 4, and 

 there is an increase to as many as 11 in some somites throughout the middle region of 



287 



TEXT-FIGURES 280 to 287. Onuphis magna Andrews. 



280. Tenth parapodium x!8. 283. Pectinate seta x310. 286. Mandible x!2. 



281. Seta from first parapodium x!93. 284. Hooded acieula x!93. 287. Portion of exposed part 



282. Seta from tenth parapodium x!93. 285. Maxilla Xl2. 



of tube xO.66. 



