38 XJNITED STATES NATIONAL MUSEUM BULLETIN 2 96 



mantle attachment disk adheres strongly to the burrow, but is removed 

 readily if the coral is decalcified. 



The average length of the aperture of twelve specimens is 0.97 mm. 

 Near the anterior end of the operculum two acute projections extend 

 to a point, but are not movable or hooked. The outer edges of the 

 thickened operculum are heavily set with teeth and long hairs. This 

 spine is tipped with many very fine hairs, which give it a fuzzy appear- 

 ance. There is no granular area representing a lateral bar. 



The inner edges have fewer teeth and hairs, and are lined by a 

 comb collar. The details of this comb collar can be seen in figure 2c. 

 The distal portion of a delicate membrane is broken into flat hairs 

 with extremely delicate fimbriation on both edges. 



The mouthparts are typical of the order, being composed of a pair 

 of mandibles with palps and two pairs of maxillae. Each mandible 

 has three strong teeth plus an inner angle resembling a compound 

 tooth, with hairs at the inner angle and along the posterior margin. 



The mandibular palp exceeds the mandible in length; with long 

 soft bristles on the edges near the tapering point. Each first maxilla 

 is armed with two strong teeth, numerous bristles, short teeth along 

 the cutting edge, and has the usual apodeme. The second pair of 

 maxUlae are large and soft, and have numerous flexible bristles dis- 

 tributed along their edges. These close-set appendages serve as pos- 

 terior limits to the mouth field. 



The mouth cirri have a two-jointed protopod upon which 

 the two bristle-bearing rami articulate. The number of segments in 

 the rami of the mouth cirri are speculative, and variable. Both rami 

 have numerous bristles, some of which are finely plumose. 



The terminal cirri have given me the most trouble, inasmuch 

 as a miscount caused me to place this species in the wrong family. 

 There are five pairs of biramous, multisegmented terminal cirri on 

 two-segmented protopods. The first terminal cirrus slants inward 

 between the other pairs (see fig. 2a), and was overlooked until an 

 attempt was made to count the segments. Figure 2g will give some 

 idea of the diSiculty in counting cirri, which is especially hard when 

 the paired cirri are compressed. The single pair of uniramous two- 

 segmented caudal appendages bear long plumose bristles. 



The segment count for the terminal cirri foUows: 



Terminal 



cirrus: 1 2 3 4 5 



Ramus: ant.* post.** ant. post. ant. post. ant. post. ant. post. 



Segments: 11 15 21 28 31 36 39 39 42 41 



♦Anterior. **Posterior. 



