4SS PROCEEDINGS OF THE ACADEMY OF [May, 



a budding zone at the distal end of the basal segment. The type speci- 

 men, which has suffered less from maceration than the others, has the 

 median tentacle with twenty-one articulations reaching to the middle 

 of VI, the inner lateral thirteen articulations reaching IV, and 

 the outer lateral seven articulations reaching II. Eyes black, some- 

 what elongated and crowded into the recess behind and between the 

 bases of the lateral tentacles. 



Peristomium considerably longer than the prostomium and slightly 

 wider than its widest part, the anterior third distinctly separated dor- 

 sally as a ring which is sometimes elevated prominently above the head. 

 The principal ring presents the usual lateral or mandibular lobes and 

 a smooth unfurrowed ventral lip. The nuchal cirri have the characters 

 of the tentacles, about equal the peristomium in length and have four 

 to seven articulations. Somite II is very short, scarcely more than 

 one-fourth of the prostomium, V is slightly enlarged, and behind it 

 the remaining somites are of nearly uniform length until they begin 

 to diminish at the posterior end. They are all smooth, simple and, 

 especiall}^ in the branchial region, very clearly defined. A short 

 cylindrical pygidium bears a pair of short stiff cirri and laterad of these, 

 but still ventral to the anus, a pair of long, slender, flexible cirri equal- 

 ling the fifteen terminal segments. 



The first parapodium is strictly ventro-lateral ; those following rise 

 gradually to a half-way level. In form they imdergo the changes 

 usual in the genus, their chief characteristic being the prominence of 

 the cirri, which are retained both dorsally and ventrally throughout the 

 entire length of the worm. The dorsal cirri are especially prominent 

 and distinctly articulated anteriorly where each consists of a larger 

 basal and two smaller jomts, together equalling the basal one. About 

 XXV one of these disappears, and a little farther on the other, the cir- 

 rus at the same time becoming more slender, but remaining about twice 

 as long as the setigerous lobe; posteriorly, as the latter becomes 

 smaller, the cirrus is relatively much more slender, three or four times 

 the length of the setigerous lobe, and often famtly articulated. The 

 ventral cirrus also, while undergoing reduction in the middle region, 

 exceeds the setigerous lobe throughout and always bears a small ter- 

 minal joint. 



The branchise are of typical uniserial pinnate form, the main stem 

 curving mediad over the back and the end not being strongly bent 

 upward. The branches are long, slender and simple but never exceed 

 the dorsal cirri; they arise from the main stem at right angles, not 

 dichotomously, and curve slightly mesiad. On two specimens they 



