LEODICID^ OF THE WEST INDIAN REGION. 69 



The maxilla is dark brown with the edges of the teeth more or less covered with a 

 whitish incrustation. 



The carrier (text-figure 233) is slender, the forceps heavy, each half with a white- 

 tipped swelling at the base, and much curved. The proximal paired plates have 3 

 prominent teeth on either side, the distal paired with 4 on the left and 7 on the right. 

 The unpaired plate has 6 teeth. A small plate with recurved edge lies lateral to each 

 terminal paired plate. This figure was drawn from a Porto Rico specimen in which the 

 number of teeth varied somewhat from those described from the Tortugas. The man- 

 dible has slender dark-brown limbs with a transparent lateral margin on either side. 

 The terminal beveled portion is covered with a white incrustation, but has dark-brown 

 margins (text-figure 234). 



Marphysa brevitentaculata, new species. 



(Plate 6, figures 13 and 14; text-figures 235 to 243.) 



A moderately large species. The prostomium is 2 mm. in diameter and the body 

 at its widest is as much as 4 mm. The type specimen, exclusive of the pygidial region, 

 measured 600 mm. and contained about 800 somites. 



There is little pigmentation on any part of the body, some specimens appearing color- 

 less and others a faint slaty blue. A faint pink tint, due to blood, may appear on various 

 parts of the body and the colors of the gills are noticeably bright (plate 6, figure 13). 



The prostomium (plate 6, figure 14) is rounded, with a very minute median constric- 

 tion, and in life is often expanded laterally so as to be wider than the first somite. There 

 are five very short colorless tentacles, not more than half as long as the prostomium. 

 Each has a fine longitudinal blood-vessel on its dorsal surface. 



The first somite (plate 6, figures 13 and 14) is about as long as the three following 

 ones. Later ones increase very gradually in length and breadth to about the middle of 

 the body; at the posterior end the narrowing is rather abrupt, the pygidium being nar- 

 row. In life the pygidium is colored green. It carries two pairs of anal cirri, one pair 

 much larger than the other. 



The first parapodium (text-figure 235) has large dorsal and ventral cirri and a long 

 cirrus-like posterior lobe. There is one dark-brown acicula. The tenth parapodium 

 (text-figure 236) has conical dorsal and ventral cirri with, on the setal lobe, a high 

 anterior lip and a large, conical posterior one. There are two dark aciculae. The 

 fiftieth parapodium (text-figure 237) has a pointed dorsal cirrus whose ventral surface is 

 lobed and a conical ventral one. The posterior lip is rounded and extends from the sur- 

 face farther than the apex of the setae. There are two dark aciculae in the setal portion and 

 needle aciculae in the dorsal cirrus. A parapodium from the region of the six-hundredth 

 (text-figure 238) has smaller setal and posterior lobes than farther forward, also one brown 

 acicula. No hooked ventral acicula was seen. 



The setae of the anterior region are of two forms, the simple ones (text-figure 239) 

 long and slender, slightly widened toward the ends, the convex borders with fine dentic- 

 ulations, the compound ones (text-figure 240) with flattened terminal joints, curved to 

 a sharp point. I could find no pectinate setae in anterior somites, but in the region of the 

 fiftieth were some very small and slender ones with about 16 very fine teeth (text-figure 

 241). The acicula (text-figure 243) is straight, dark-colored to very near the apex. 



In the type specimen the gills begin as 2 filaments on the left side of somite 39 and 

 on the right side of somite 37. There are some irregularities in the number of the fila- 

 ments, but they very soon increase to as many as 5 and in later somites there are 8 (text- 

 figure 238). They arise from a broad base which narrows rapidly toward the point of 

 origin of the terminal filament. 



