106 UNITED STATES NATIONAL MUSEUM BULLETIN 29 6 



the array of armature on the operculum becomes impressive. Two 

 large hillocks are found on each side, each bearing about two long, 

 serrated spines, one to three short, heavy knobs bearing a large 

 number of teeth and tubercles, and numerous flexible hairs. At the 

 attachment end of the operculum is an array of many slender spines. 

 A row of about 15 short, serrated teeth line the lateral margin of each 

 operculum. 



The typical comb coUar lines the mantle aperture, and an array 

 of bicuspid teeth are just below the aperture externally in almost a 

 single complete ring. 



The lateral bar is very light and seemingly fragile. Its anterior end 

 frays out toward the aperture, and the posterior end terminates a 

 little short of a heavy tooth averaging two or three cusps. No 

 discernable row of teeth are associated with the lateral bar, but 

 small teeth are scattered about on the mantle, especially in the 

 area of the posterior end of the lateral bar. A thin, single, dorsal 

 reinforcing rod extends the length of the neck. The neck is a deep 

 brick red in the dried state for essentially its entire length. 



The body is typical of the genus. A long labrum extends to the 

 aperture. The mouthparts are typical. A very small mouth cirrus 

 with just two hairs was found. 



The terminal cirri are three pairs of biramous cirri on a two- 

 segmented protopod with slanting sutures. The segment count of 

 these cirri indicated 15 to 18 segments, a low number for the genus. 

 The setation of these segments is typical. On the inner curvature 

 two pairs of bristles of essentially equal length of about two to two 

 and a half times the segment length is found on each segment. On 

 the outer curvature a plumose, single seta of two to five times the 

 segment length occurs on every few segments. The longer setae 

 are found especially at the base of the first ramus. 



The digestive tract also is typical. An esophagus leads from the 

 mouth field to a gizzard. The gizzard has a triturating mill which looks 

 like a mulberry cut in half and reversed, then each half scored down 

 the middle, to make four quarters, each of about 16 nodules. The 

 whole mUl is set in a framework of muscles with four nearly straight 

 bands of nine to twelve bumps. These remain after boiling in KOH, 

 so they are not just muscles. Below the mUl, and still within the frame- 

 work of bands, is the usual "strainer" of fine striations. 



The male : The male is equipped with a pair of antennules, a large 

 penis, and four chitinous teeth at the posterior end (fig. 27g). The 

 body wall is sUghtly annulated in the midregion. The penis, after 

 KOH treatment, does not show much annulation, but has what appears 

 to be a chitinous tip. No naupliar eye or yellow organ was seen. 



