LEODICID.E OF THE WEST INDIAN REGION. 



Ill 



lobe. The setse (text-figure 412) are long and slender, sharp-pointed, with a narrow 

 wing. Both axis and wing are striated. 



The maxilla (text-figm-e 413) has a very slender carrier prolonged into slender 

 rods. The forceps is feebly denticulated at the base, the halves much curved. The 

 proximal paired plates have each 5 teeth, the second pair 4, and the third pair 2. A 

 dark-gray triangular patch of chitin is attached to the base of the carriers. A pair of 

 black plates are attached to the wall of the pharynx and probably represent the mandible. 

 The figure shows their position with respect to the maxilla when in place in the pharynx. 



Collected in April 1918, on Buccoo Reef, Tobago. 



Type in the American Museum of Natural History. 



V 

 Drilonereis similis, new species. 



(Plate 8, figure 12; text-figures 414 to 417.) 



A medium-sized species of this genus, reaching a width of 0.75 mm. 



The prostomium is long and conical and there is no trace of eyes. When fully 

 extended (plate 8, figure 12) the anterior end shows a gradual increase in widtn from the 

 prostomium back for about 30 somites. The anterior end is a light grayish-yellow, while 

 farther back in the body there is more color, due 

 to the blood in the vessels. There is very little iri- 

 descence. The black maxillse can be seen through 

 the translucent body-wall and are often protruded 

 from the mouth. 



The parapodia are practically not present in 

 anterior somites, the setse arising from the body- 

 wall. When developed (text-figure 414), the para- 

 podium has a prominent posterior lobe, a rounded 

 setal one from which an acicula protrudes, and a 

 tuft of setge. A parapodium from the posterior 

 end of the body (text-figure 415) has the posterior 

 lobe as a rounded knob with a very heavy acicula 

 extending to a considerable distance from the sur- 

 face of the setal portion. There are a few stout 

 setfe. The setse are all similar in form; each (text- 

 figure 416) has a shaft, curved toward the apex, 

 which is sharp-pointed and has a rounded wing 

 on the convex surface; they somewhat resemble 

 the setse of D. brunnea, but have a shorter wing. 



The maxilla (text-figure 417) has an elongated 

 carrier with slender basal processes and a brown, 

 ventrally attached plate. The forceps has heavy 

 bases with prominent teeth on the inner margins 

 and with slender terminal portions. The proximal 



paired plates have each a very large tooth at the distal end with a row of three smaller 

 ones proximal to it. The second and third paired plates have each one tooth. 



Collected in April 1918, at Petit Trou Lagoon and at Buccoo Reef, Tobago. 



Type in the American Museum of Natural History. 



Drilonereis brunnea, new species. 



(Text-figures 418 to 420.) 



A large species for this genus, the type specimen measuring, after preservation, 

 275 mm. in length, and containing approximately 440 somites. The prostomium is 

 1 mm. wide at the base, tapering to about one-third of that width at the apex. The 



Text-figures 414 to 417. 



Drilonereis similis Treadwell. 



414. Anterior parapodium x80. 



41.5. Posterior parapodium x80. 



416. Seta x3S0. 



417. Maxilla x5.5. 



