LEODICID^E OF THE WEST INDIAN REGION. 75 



a hood; a second form of compound seta (text-figure 263) having basal portions much 

 like the other, but with long, pointed terminal joints; one margin of these is roughened, 

 but I could discover no true denticulation. The third form of seta is simple, shorter, but 

 not in other respects differing from those found in later somites. In middle somites 

 the compound setse (text-figure 264) have basal portions much like those of the first 

 parapodium, but the terminal joints are shorter and stouter and with a basal blunt 

 tooth not found in the others. The simple setse of later somites (text-figure 265) are 

 long and slender, very sharp pointed at the apex, more or less bent, and with a narrow 

 wing along the bend. This general form of seta, with variations in the degree of bending 

 and in length, occurs in all parapodia. I was unable to find pectinate setse in anterior 

 somites, but a few occurred in the region of the one hundred and tenth. I did not attempt 

 to determine their precise distribution. They have slender shafts, the end rather wide, 

 with about 20 teeth, both terminal ones being longer than the others. In parapodia 

 toward the posterior end of the body they become more numerous and with longer 

 shafts, but I could find no important differences in form (text-figure 268). 



The dorsal aciculae of the middle region (text-figure 266) are smooth at the end, 

 which is colorless, the middle region being a dark brown, which appears as black under 

 low power. Through the middle and posterior regions I could find only one acicula to 

 a parapodium. The ventral acicula (text-figure 267) is much smaller than the dorsal 

 and is colorless. 



The jaw apparatus was removed for examination and unfortunately lost before a 

 drawing was made, so that nothing can be said about its structure. 



Marphysa languida somewhat resembles a small M.acicularum (see p. 57), but differs 

 in that the gills begin much farther back on the body and never have more than two 

 filaments to a gill. The incomplete specimen was larger than the type, but agreed with 

 it in all details. 



The type is in the American Museum of Natural History. 



